Poor customer service

Presently my account with Truworths is or should be about R900 in credit, so why's that. I unfortunately did not put the correct reference with my payments with the result I was inundated with demands and threats for payment by sms's, emails and phone calls. I was handed over to Blake & Associates, despite the fact that I forwarded about 15 proof of payments. So eventually I paid R1500 to settle and close my account because of the harassments. So at least the emails could have been checked and followed up.