Just make sure it is at least one month, otherwise they will say you didnt give enough notice and continue to bill you for the next month. Bastards. I'm sure the Consumer Protection Act made it THEIR responsibility to ASK YOU if you would like to continue month to month, but there is no enforcement of the CPA so they continue to do whatever they want until you start arguing.
As for PE reception in western suburbs, it is crap. Edge most of the time, and when I phone my family in PE from Jozi, it always cuts out and sounds like they are all sitting inside a tin can.