You gave them a credit card, but have not yet been charged.
1. Find the Trial Period and Charge
Hidden charges come from a monthly subscription after a free trial period of 1-7 days. 
If you are within that trial period you must go to the site and cancel.
You should have an email confirmation – assuming you used a real e-mail. That email will have the billing web site where you can cancel. If you do not have it, look in your spam folder. Also look in your trash folder – you might have received an email that looked like spam an you just deleted it.
What the Charge Looks Like
The charges will appear under a site name that provides discreet billing. That name does not reflect the scam site that you started at, nor the dating/adult service. It might be a very generic name like PerZoneBill.com, or it could be gibberish such as abpardt.com. This page has a billing site search that might help:
Your browsing history
Will help you determine if the charges were hidden, or if you should have known you would be charged. Find the site you visited and look very closely. Look at the source code, and look for the iFrame then click on it directly.
Might not help you determine who might charge you (what site you need to cancel). Even if you go the site and find where you were re-directed, the billing sites change frequently. What you find might not be the charge on your credit card.
The good news is, even though the sites change, they usually use the same customer service company behind the scenes. So if you were charged by abcdates.com, you might be able to cancel it at xyzdates.com.
2. Cancel the service and ask for a full refund
In the United States, cardholder agreements require that you make a good faith effort with the merchant to correct the situation. Therefore, even if you think you were scammed, you need to work with them.
Remember, the charges are recurring monthly fees. More charges will show up again on your credit card statement if you do not act quickly. Also, If you do not act quickly, you diminish your legal right to dispute the charge.
Assuming you found an email or the website that charged you, then you will need to call the customer service number at the site to ask for a refund. You might need to give them a partial credit card number. That is OK, here’s why:
Providing Partial Credit Card Number
If you cannot get a full refund, then Dispute the Charge. You can work directly with your bank if you are declaring a fraudulent transaction (disputing the charge). Remember, you are alleging a crime so be certain.
This section assumes you were scammed in to signing up. If you knew, or should have known you would be charged, you need to pay the bill.
3. Cancel your credit card and get a new one
I know this is going to be a hassle, but trust me, this is necessary. You do not know who has your credit card information.
The first big reason is that you are at risk of Identity Theft. This could be thru an overt act on the part of the one of the unknown entities that has your credit card, or an inadvertent act because of lax security policies and practices.
Canceling your card will ensure you do not incur further charges. I frequently receive emails from people stating that they cancelled the service, yet the charges keep coming. There are often bonus offers, which are trial periods that turn in to expensive monthly subscriptions. Also, keep in mind that your personal and financial information might have been shared with affiliates.
4. Opt out of the Card Updater service.
When you get a new card, tell your bank that you want to opt-out of the Card Updater service. Card Updater provides merchants your new credit card number when it changes. This keeps subscription services uninterrupted. For VISA, its called Account Updater. MasterCard calls it Automatic Billing Updater.
Opt-out is provided by most major financial institutions. If your bank does not allow you to opt-out, find a new bank.
5. Work with your Bank to Dispute the Charges
If you have beens scammed, and the site will not refund your money, you will need to work with your bank or credit card issuer. Before you do, it is best that you are completely informed so you know how to best handle the situation.
1. Read my supporting article: Date Verification Scam. The article provides:
- Details of how the scam works – important so that you can explain to the bank exactly what happened, and why this is not a case of forgetting about a membership trial period
- A way to independently verify everything in these articles
2. Read and Bookmark this page: Credit Card Dispute Process. This page will cover:
- What you need to do to have the charges removed
- Rights as a credit card holder
- A sample narrative and letter to use to communicate with your bank
6. Get a Credit Monitoring Service.
The credit monitoring service will help protect against identity theft. The fact that an unknown company has your credit card means you are at risk of Identity Theft. Remember, we do not know who has your personal financial information. The stated privacy policy on the sites reveal that risk in plain language. Since we do not know who has processed your credit card, we do not know what will happen if there is a breach.
I recomend Identity Guard a Trusted Leader in Identity Protection. You will have a choice on how you protect yourself. Its a good company, and I like the way they have treated me. As former IBM employee, I guess I am partial to the Watson by IBM technology. Watson uses artificial intelligence to assess threats to your identity.
Full Disclosure: The links on this page are affiliate links. Identity Guard. I get a small commission, at no cost to you if you use a link on my site. There is usually a discount if you use my link. This helps pay the cost of this site.
This is important. I only want you to make a commitment if you are comfortable that this is the right thing for you. Only you know what happened to you, and your situation.
Source: https://www.iii.org/fact-statistic/facts-statistics-identity-theft-and-cybercrime