I would never in a million years sign up for an SMS service like that, yet I have been signed up for things like that no less than three times during the several years I have been a customer of T-Mobile. I have just managed to catch the charges on my bill. T-Mobile's customer support has always been accommodating, and in most cases, they have been able to refund my money. They will also put a block on your account for "premium services" if you ask them to.