Texting and Illegal phone

I bought a new Razr phone last year and installed my card in it and it works great but I received some unwanted text messages and ATT charged me since I don't have any that service. I call ATT and asked if they could block me from text messages since I don't want to receive them never had never will. They first said since I didn't have a contract they couldn't do anything. I called and talked to someone else the next time I received a bill for a text message and they said I didn't have a contract and asked what phone I had and I told them it was a razr. They said it was illegal for me to have that phone and said I needed to bring the phone in. Is their anyway to stop the charges for text messages since I don't use text messaging and don't know the people sending them.

vanman250