Rcs

I have an account with jet which is now under rcs, so I've been paying my account in jet store and their tfg group stores and I was always upto date. So some months I would pay my account through my banking app using my account number as reference as their email says when they send a statement.. I paid into their FNB account. In July I realised that my the money is not going down on my statement and I called to get clarity but they failed to give me clarity. I called again until I was told that I missed payments which I did not. I send them my bank statement with my account number as reference showing that I paid, they took me from piller to post and demanded that I sent proof of payment from the bank which I did too but still the issue is still not resolved and I'm getting calls non stop and emails saying my account is in arrears. Worst of all is this is affecting my credit score. Please help me get my money allocated into my account and my name be cleared.