Unauthorized charges for almost a year

In April 2025, I added a second line to my Mobile account. This was for a friend, they used it maybe a month or two at the end of May early June I contacted support, requesting to disconnect the second line as it wasn’t needed. I was assured, after being transferred to multiple different agents that the line was disconnected, and I would not be billed any further. I went into the app and I saw that the second line was still there contacted support who assured me that the line was disconnected and I was not being billed anymore for this service. My phone bill usually runs $34.25 with the second line it was at $70-$80 a month. I also had Internet and I had auto pay set up so I didn’t really pay attention to every bill I just knew that they were charging me every month for Internet phone altogether they should have been about $80 a month with just my phone and my Internet. I went into the app a few other times kept seeing the second line there kept contacting support telling them that I had requested to disconnect the line. They assured me that it was just there and they didn’t know how to get it removed from my app, but to rest assured I was not being billed. The end of 2025 I ended up being put on a repayment plan which was 51.25 a month. My current outstanding bill is 400 some dollars. Which would not add up to being just my phone. So a couple weeks ago I go and pay all my repayment plan. I didn’t have any service or contacted support. I was sent a photo of my Mobile billing, which was more detailed than any other bill that I have seen which said the second line was still on there so I was still paying the $47 a month for the second line that I had requested to disconnect almost a year ago. I can’t I’m on the line with support agent actually knew how to troubleshoot and take care of my issue. Unlike the other ones who just transfer you all over because they don’t wanna do any work I assume or they just don’t know how. The agent checked past conversations and could see that I kept asking if the line was disconnected, and I was told it was which it was not. I was credited $60 towards my bill however they did not credit the unauthorized charges to my account or refund me. They also didn’t subtract that second line from that outstanding bill so here they are trying to [Edited: "Language"] more. So they lied to me for almost a year and stealing money from a customer. This is ridiculous. I also paid towards my repayment plan and was credited to 60 some dollars so it came to about 115 or so and then they cut my phone off and suspended the line after two weeks and then said that I didn’t pay 100 and some dollars when it was due, so they suspended my line which they owe me money since they like to lie to their customers and make fraudulent charges to their cards. I guess I have to report them for their unethical business practices.  It would be nice if they actually hired people with common sense and who actually listened to their customers when they spoke instead of acting like they already know the answer when the customer hasn’t even said anything, they have the worst customer support ever.

i wanted the money they fraudulently took to be credited to my account but not until they subtract the actual overdue amount.  
I guess I have to either dispute the charges for that second line and report them to get anywhere, since they like to hang up on customers and not call them back. Go figure the only support agent who resolves issues never got disconnected in the hour I was being serviced.