Problems with billing

I have a contract with Autopage and since September 2014 I've been battling with my a/c. I have a Pay as you go acc witch means you pay the same amount every month but the suddenly I receive an acc for Over R3000- rand and then the amounts kept changing and the money goes off by stop order so very time I must go to the branch in Polokwane and try and sort this out with no satisfaction. They even cut the service off twice. I'm not getting any satisfaction from this company now I'm not going to pay them anything any more and they can take met to court I don't care. There customer service is pethetic !!!