There is a place on Main road, just before it becomes Bram Fischer or just after, not quite sure. But it's on your right as you drive from Bryanston towards Linden..
Yes it can get quite expensive. Anything from R600 to R800. Insurance pays about R1000 per rim that needs to be painted.
Fixing rims are quite easy and is the same proccess as painting cars use the same paint too.
Ms Primer, Close hole with stopper fine, 1k grey primer over the stopper fine, basecoat for metalics and the clear coat or if its like a black rim you can put basecoat black and clear or use 2k black to paint it.
Steel rims can also be painted but needs more tlc cause they need ETCH primer on them
Panel beaters can also do your rims so you could also get quotes at panel shops.