If you play by their rules, it's not hard. If it's a residential line, you (must be the line 'owner' who does it) have to fill in the form, available on their website, and email it. You can't hand it in at a Telkom shop - which you can do if it's a business line. Then you wait. After about a month they phoned to say it was done. And, in our case, our next bill had a charge of R231.88 ex VAT, for an "Exchange Conn Conversion". I liked their choice of "conn". In our case we were "cancelling" our DSL connection (kept the voice line for now) and moving to Openserve fibre, which is still Telkom.
As for SABC, I had to cancel one for an elderly relative a couple of years back. I phoned and found out what had to go in the affidavit, did that, got the police to stamp, scanned and emailed to [email protected] and got the cancellation notification the next day. Not sure what their cancellation period is, but the relative had paid for the year anyway.
I also want to cancel, do you guys think this could work if I downgrade my 4mbps 'do Advanced' package (R575+/- p.m.) to the 'do Lite' 1mbps package (R279 p.m.), let them action that (I'm assuming a few days at most for them to do it?) and then I give my 30 days line cancellation and only then owe them another R279 for the remaining 30 days?