Check with your accounrs!

Finally at the end of the year I can terminate my contract and I am counting every sleep till D day. I made a payment of just more than my outstanding monthly amount and also received confirmation via sms from them thanking me for my payment. Now almost a WEEK later they call me to ever so politely demand me to pay my account afer that I told her that I already paid my account a week ago an d received an message from them to confirm it them she said no it’s fine she will follow it up with her accounts department. WHY O WHY did she not do that before she starts phoning people demanding money from people? Totally unacceptable and unprofessional. In the 2 years now that I have been with them, I have paid my account every month. One or two months maybe a little late but I never have not paid my account.