So I've decided to give up on getting ADSL. For two reasons.
Firstly, I don't think Telkom will actually give it to me where I currently live. They've had various contradictory excuses about why they can't give me ADSL, and I'm really just sick of fighting.
Secondly, we have to move out at the end of the year, and so it doesn't make sense to order it, wait 2 months, and then just as we get it, we move out.