Bad service

So my car has been at Renew it Rivonia since the 13 April to date . Authorization for repairs was done 2 weeks later on the 22 April 2021. I had a curtousy car the same day of rhe accident. Ans I am supposed to return it tomorrow and remain stranded since my car hasn't been fixed yet and my so called insurance canceled the car rental even though they delayed with the authorization. What kind of a service does Iwyze give to their client?

How do we remain clients with such a bad service we get from the service provider?