AT&T wireless customers may have been receiving unwanted monthly charges for third-party services they did not even know about. Now, because of a settlement between AT&T and the Federal Trade Commission, AT&T must refund those customers and pay some fines as well, CNet reports.

Customers who were receiving these unwanted charges were notified in their recent bills. Those who chose to get paperless billing were sent an email. These customers have until Friday to ask for a refund for the unwanted charges.

These third-party services were charging fees of about $10 per month for ringtones, horoscopes and love tips. Many customers did not even notice the charges on their bills.

The FTC has been cracking down on companies that allow these third party services to add monthly charges to customers' wireless bills. The practice is known as "cramming."

AT&T settled their case with the FTC for $105 million in October. The other three main carriers have also been accused of cramming as well. T-Mobile settled their case with the FTC for $90 million in December.

AT&T will pay the FTC $80 million and that money will be used to refund customers for the unwanted charges. They will also pay another $20 million to 50 states and Washington, D.C., and $5 million to the Federal Communications Commission.

In the complaint against AT&T, the FTC said that AT&T kept at least 35 percent of the amounts that were charged to customers.

AT&T was required to alert customers who were eligible for a refund for the cramming charges. The settlement required the company to send three separate text messages to customers to tell them they were eligible for a refund.

If customers are not sure if they are eligible for a refund, they are to call 1-877-819-9692. They can also apply for their refunds on the FTC's website.