Telkom is robbing me.

I took a contract with telkom which I was supposed to pay R399 every month and ever since I've started using this service provider , they debit more than what I agreed on . Every time i call in to try and find out why my accound is always over debited , they tell me their systems are down & there's nothing they can do to help me. The second last debit order that went off , an hour later, my line was suspended . Why the **** do I pay for something I barely use? I reversed my money because i had no networks and when i called in they told me about their ****in system . On the 31st of January 2019, they debited R1647,25 and still today , my line is suspended. How ****ed is that?