Credit Issue @ the cause TMobile Agent

Hi, I have an issue with my credit report due to a lady agent I spoke to over the phone applying nearly $700.00 my boyfriend and I paid, toward our BILL instead of paying off the phones like I’d asked her to. I asked if the phones would be paid off and she said yes. After 6-7 months with auto pay attached, my boyfriend and I had no idea that we weren’t being charged monthly for our phone bill because the AGENT’s incompetence for understanding that NO CUSTOMER is going to ask to put that much money toward a monthly bill. We were also not receiving paper mail, to notice this discrepancy ahead. We paid to pay off the phones in full. I called in because I noticed the account did not change at all and we were paying off the same amount just monthly ahead as a credit of our own money to the account. Who do I speak to, to get this off my report. This was not our fault, it was TMobile’s and I’ve seen other questions and comments like this here as well.