USBI Third Party Billing company Stealing money, unauthorized charges, fraud internet Nationwide

While veiwing my AT&T bill, I discover a fee for USBI. I use the "Live Chat" to find out what USBI meant. The representative for AT&T told me that they are  a third party company billing me and if there are unauthorized charges to call them directly for a refund. I researched them further on the internet to find that more individuals have been having issues with this company for over 9 years. I could only go as far back as 1 year on my bill, and they have charged me over $164.00 and I am quite sure it goes further back. Each month, the fee varies anywhere from 6.69 to 21.84. I would appreciate some direction on how to get a refund. Especially considering that my research proves that no one has had luck and it seems the charges are still on their bills today.

Thank you,