Being charged for service I don't have

Hi,

A credit card mixup lead to my card being charged for my boyfriend's cell bill. Now we can't get ATT to stop charging me. He has tried calling ATT and updating his billing info several times, but I still get charged. I finally closed that credit card, but this month ATT withdrew the money from my checking account. Let me be clear - I have absolutely no association with this account. I find it completely outrageous that I continue to be charged for another person's cell phone service despite multiple tries to fix this with ATT customer service. Please tell me how you will fix this for good.

Thank you,

Jennifer