I had this charge on my ATT bill. I too have never authorized this or answered a text that would have started this. I am certain of this. Called ATT, they are able to go back 60 days and refund. I have been charged for this for 7 months, and never realized it.
I looked on this site and saw message above. I called 800-416-6129. The guy told me I had reached the mobile help desk for Mobile Messenger. He needed the 5digit ID next to my charge on bill. He found the "subscription". He said he could refund 3 months now, or I could fax in bill to 310-496-2873 and they would refund ALL charges. Refund comes in form of a check, gave me confirmaton number. I went ahead and just took the 3 months refund from him, plus the 2 months credit ATT will put on my bill. I didnt want to mess with faxing the copies of my bill. So, its a mess, but at least I am able to get a refund. Now that I think about it, I could have faxed my bill, received the 7 months refund AND the ATT credit, and end up making money off them...but, karma...