Frustrated client

I have an RCS store card and ever since i've had this account,i've been making EFT payments.these payments were received every month up untill July 2018.i've been received calls and smses from yhe customer care people stating that my account is in arrears.i've sent the proof of payments to show that the account has been paid but still nothing has been updated on my account.i have been back and forth wiyh consultants telling me to do this and that but no response from them.i was promised a call back so many times after they've seen the documents,but nothing has happened.interest is accumulating on my account and it is causing a bad record on my name .i spoke to quitr a few supervisors promising me that they will resolve the matter but nothing.im spending alot of money phoning and holding on for over 20minutes just to explain my situation to every consultant.it is now at the stage where myself and the consultants are rude with each other because i am frustrated. They havr the poorest of poor service and i wouldnt advice anybody to get involved with these ******.