What a bizarre concept that the dealer offers the service...but then doesn’t have someone to do it.
It simply opens them up to all sorts of issues doing something on the behalf of someone they don’t know or trust.
And then why use the dealer and not simply go there directly?
Also your insurance can cover this, reach out to them and claim for it and have them recommend someone.
I'm not sure I understand?
It's not a service and the question wasn't really about the process ?
But to answer, going direct to these rim places means taking time off work and going to some of the most dodgy industrial areas in Johannesburg.
These rim places either then keep your car locked up on their premises for a few nights while they carry out the work for you
Or they give you replacement 'wheel's to use for a while, often being an incorrect size and a bit screwed up too. They kinda mess up your sensors temporarily (tyre pressure / ABS etc)
Or
As the car is under warranty, rather pay the dealer to remove all the four wheels at the same time, point them to the rim place. they drive and drop them off / collect them when they're done. The car stays at the dealer on their lift and dealer charges 1 hour labour for the convenience factor.
The dealer pretty much says 'oh yea ... you're bringing your car here anyhow for a service - so as a favour, we're happy to drop/collect wheels on your behalf - and we'll keep the car safe at the dealer. Just point us to wherever you feel is the best place and we'll handle the rest'
EDIT : They do the same with chipped windows, small dents, wheel alignment or balancing - they can do everything at the time of your service, rather than needing to go for the service AND PG glass AND Tiger Wheel AND Metal Cross