MTN Welkom Square

Hi I've been having 2 contracts at MTN in Welkom Square in Welkom. I canceled my phone contracts few months ago and now suddenly they saying that I'm owing more than R1300. I paid every month and I'm trying to cancel my router contract now but everytime i go they have stories and tell me I should call a number which they never answer. They have really bad customer service and they are very sly. Telling me I'm behind with payments everytime or their system is down if I go into the shop. I wouldn't recommend them at all. My account number is:BA***