money disappearing

I have been trying to reach Telkom forever now with no success. I acknowledge there was a negative balance on my account which I was rectifying, then Telkom deducts a nice chunk of money out of my account, and suddenly my account increases instead of deducting. now my lines are being suspended and no one can answer where my money has gone to. how od you pay of something when it keeps increasing? they take money and it just disappears. this is absolutely ridiculous