No respone from RCS on account query

I have been having the same problem with RCS and I got an sms threatening legal action because somehow they said I didn't pay my account. I called them to rectify their mistake and provided my proof of payment and this was done on 16/07/2018. I have sent numerous emails after that to see to it that the error has been fixed but no one has come back to me. This is really unfair as it affects my credit report and I never skipped any payments since opening the account. Can someone please attend to this issue urgently.