If the person or company goes to the police and is able to make a case, and there is sufficient reason to believe you are downloading (and selling) illegal content, yes Telkom can provide the needed info to track you down (If I am wrong please tell me). But if you are worried about downloading pirate content, don't be.
The chances of a company or person actually able to make a case against a single person downloading pirate content is 10000000 to 1. It's only when you start selling pirate content that there is a sufficient risk of prosecution.
When it comes to other illegal content like i.e. pr0n, I would be very careful as there is much more being done about cases in these categories.
So in other words, daily there are millions of people only in South Africa downloading and using pirate content, the chances of you being tracked to your house by Telkom is almost nothing