RCS does not want to close my account after settling it

I have had such a horrible experience with RCS and I will never open an account with them again.

I settled my account in 2018 however every month its still accumulating and saying I'm owing. I've been sending emails to rcs telling them about this issue. they would clear my balance but the following month I would get another statement with a new balance. This happened for over 2 years. Until this year I opted them to close my account. I sent an email they said they would close it but they didn't. I went to Game store to ask them to close it, they said they would first clear the amount I was owing then close it. It has been over 6 months now and my account is still active and I'm still owing. This has a negative impact on my credit score. My credit report shows that my RCS account is in arrears and I have missed payments, whereas I settled the amount 2 years ago.