T-Mobile has been overcharging me for months

Switching from Sprint to TMobile (forced) led to them inputting the wrong address (I'm in Michigan, the address was Bronx, NY) so we were charged taxes in a different state for the past year. We don't do direct billing because we like to get a bill in the mail. Many times reaching out and asking stores why we can't get a paper bill only led to them encouraging us to do it paperless. Uh huh. so many months later (my husband pays the bills so i didn't know), I had to go online to our account and see if I could change the plan, lower my bill a bit, etc. I see the wrong address. I then see additional $10 monthly data charges on each of our lines, including the 'free one' they added without us needing to say it was ok. It's a 'gift'. Yeah, ok. Then I start looking back and over the past year it was $30-40 a month additional and they won't reimburse it. They said they offer Magenta, but brought us over and didn't change our bill. But what they didn't say was their plan INCLUDED that added data we carried from Sprint (they added the charge when the plan we were on didn't have data at the time). So they are reimbursing the taxes difference and we got the $40 a month taken off GOING FORWARD. So, Claims and BBB and whatever else my lawyer friend suggests.