I tried signing up directly with CISP now.
Firstly, on the provider selection page, they don't have an option for Metro Fibre in Pretoria, only Johannesburg. I went with that, not sure if that would be a problem.
Second issue was them asking for my banking details and accepting T's and C's for a debit order, before they've done a fukin thing, so I don't feel comfortable with that as I have no idea what/when they will debit me for the first time, i.e. if it's installation costs etc. I will need to be prepared for it as well.
At this stage I may as well try Metro Fibre and see out the 3 month contract, and if it goes well, remain with them.