Nissan SA parts logistics system very inefficient

Very disappointed on Nissan SA parts logistics system, got the accident on the 14 feb 21, car taken to the panelbeater on the 23 feb 21. First orderd was delivered after 3 weeks and one of the parts delivered was incorrect, had to be sent back and the panelbeater placed a reorder together wit a new order on the 7 Apri 21 im told that ETA is 31 May 21. Mind you this is a order of a basic popular parts, a left fender and front left door. My car has been stored at the panelbeater for more than a month now just because Nissan SA can't efficiently supply the parts of the cars that their sell to public, i have lodge a query with Nissan SA customer care and after investigation with Nissan SA procurement dept, the feed back i got is that the ETA (estimated time of Arrival) is 31 May 21, i have been paying paying for car expenses, i use the car to go to work and its very clear that there is something wrong with Nissan SA parts distribution, i request that i should be provided with a courtesy car becuase this is all due to their inefficiency and they refuse. Been speaking to Gopolanang from thier customer care department he made it clear that that becuase thier parts are not made local, i must just accept the ETA as it is. So why sell vehicles that you cant provides parts for?