This is how it worked: T-Mobile charged customers on behalf of another company (third party) which in return got a "kickback" of the services charged. Customers could've requested a refund IF they had found out. If the customer did not realize, then T-Mobile would continue to charge them month after month for services they never even knew they had! Even after some customers requested a refund, the company would only give a partial refund! And T-Mobile knew they were doing this all along!
But just like professional scammers, T-Mobile couldn't stop. This was like free money! And who was going to stop them?! How about the FTC! The ruling came down this past December. In the settlement, T-Mobile will have to pay $90 million in refunds to customers! T-Mobile should feel lucky that it wasn't worse! If you suspect any cramming, call your phone carrier and/or file a complaint online with the FTC!