Disgusting service and *******

I joined supersonic and my contract said if i cancel within 6months i pay R600 cancellation fee. I contacted them and let them know that i am changing location and asked if they can check coverage for that location. I was then told that there is no coverage at that location so i had no option but to cancel. now one of the supersonic agent tells me that i have to pay R3900+ As claw back fee (which apparently includes payment i didn’t make in October). I then told her that i make payment on the 25th of each month and sent her proof of payment for the month and all she could say was “shame sisi”. The contact states that when you cancel within 6months, you pay R600 cancellation fee! Supersonic never has good internet and now you want to rip us off and your disgusting and disturbing customer service.