Phone is being held hostage by T-Mobile

I have 3 devices that I paid off. I spent over $3000 and I paid all my bills on time. My fiancé went to pay the phones off so we could go to prepaid. Cause my bill kept climbing and climbing,good customer that always paid 10 days early. They decided 2 hold the bill for 3 weeks and then say that I didn't pay my final bill when I was already started with prepaid. And they had me at $80 plus $50 plus $30 for all phones to be transferred over. So they got me for more money on top now they're pulling this that I owe our $198. They locked all my phones and one device doesn't even have service. It was a free phone that they gave me and in the end they charged me a $100 because I decided to cancel their service, which their service was ridiculous. They lied they gave me 55 plus and I wasn't 55. I'm 48 years old. They knew this and they took the deal back and my bill kept climbing and climbing and climbing. This company is a hostage company and they should be closed. Shame on you for acting out and trying to control someone's phone when they own it outright. And we're good customers all the way through the bill period And I'm on prepaid and I can't even get my phone's unlocked if I wanna go somewhere else because they don't wanna lose me as a carrier customer because they know that I pay on time very unhappy with T-Mobile. I'm really wanting to sue them and complain.