Syzgy78, first, take record of this to Telkom, and demand a refund. They will refuse you. Your next step is to call the regional manager. At this step, they will ooh and ahhh, and tell you that they are "doing tests" on your line (which they are not). In about three weeks time, Telkom will contact you and tell you that your line is fine and they will not be refunding you the cash.
Your next step is to escalate your complaint to the CEO's office. You'll get the same BS, "We've done extensive tests on your line, there is nothing wrong, it is your computer settings, it's your fault, etc etc". After this, you have one of two choices:
You can either:
A) Ask for an arbitration procedure (I don't knwo what the costs of this are) OR
B) Take your complaint, along with all your phone records of correspondance (times, dates, people spoken to) to ICASA. Write up a complaint to ICASA, and ask ICASA to decide on the matter.
I know that path B) has worked before. I have never heard of someone taking path A) before.
You can email me if you want to know more! That's if you want to have your problem sorted out. Alternatively, I suggest you search for the thread that advises people on how to prevent Infinitcall disconnections. There is some very useful information in that thread.