TFG Incompetence wrt Electronic payments

Made a purchase on 2 Apr, EFT paid an installment of R350 on 17 Apr (proof of payment sent on 17 Apr), 2 May i got an email and numerous SMSs "OOPS YOU FORGOT PAYMENT". When they called me eventually again on 6 AMay and i decided to "not block spam" i explained the situation and AGAIN had to resend the proof of payment to the Debtors Team Leader and she promised she will forward it to the relevant department and it will be sorted out. Oh and according to the agent "the system had not been updated, hence my payment did not reflect. Today 13/05. still no statement, and called to confirm my account status before i make the next payment, only to find out, I am STILL outstanding, had to RESEND proof of payment again, and in the meantime, i get charged Interest, and i'm just told "to wait" Mind you, this is NOT the first time i am having issues with regards to this form of payment. and the email addresses and reference to use, i was informed by TFG Staff what to use, Now i'm being told it's the incorrect emails. BUT WHERE IS MY PAYMENT and my Credit score will be affected due to TFG Lack of competence. !!! HELP