Arrear Letter received for payment made

I received a letter on 26/03/15 regarding my Tekkie Town account. They claimed it was in arrears, but I paid my account on 28/02/15. I called RCS on *** & spoke to a Customer Service Consultant, Daniel Allam. He was unable to provide me with any answers to the questions. He claimed that my account was short-paid but he could not confirm the date of the short-payment. He claimed that I was in arrears in January, and was supposed to pay R451. The January statement showed no amount in arrears. He kept blaming their systems, and was not able to assist me. I found him to be ***********. I initially asked to speak to a senior manager, but apparently, all managers were in a meeting. He told me that his manager would call me. By 11:00 I did not receive any call. Afterwards I called the Accounts Department to speak to the manager, Dalene Daniels. She was only available after 12:30, and I was promised that she would call me back by 12:45 on my cell phone number I left with the consultant but no-one called. I had a similar case with RCS last year. I was furious when I read the letter as I paid on 28/02/15. I would like a written apology for the inconvenience and embarrassment caused.