Telkom account threats

Telkom is really bad with accounts. I am threatened every month, although they get their money every month. Every 2 to 3 months my account 'is in arrears' for 2 months. This month they deducted an extra R1000 from my account and they have the odacity to threaten me again by saying I am 2 months behind. This is getting out of hand. How many other people don't get ripped of like this? They are probably making at least a billion rand extra profit by doing this. I won't even refer my worst enemy to Telkom.