Momentum doesn't value it's clients

I'm annoyed with this insurer,

I was supposed to get my car on the 6th of April 2023, and because of the incompetence of the claims department, I still don't have my car, which is waiting for Momentum to replace the rear windscreen. The panel beater authorized to repair my car had sent an email in December 2022 ( 5 months ago) informing Momentum of the authorization that should be issued to a glass company for the replacement of the rear windscreen once they are done, so that the glass company can have enough time to order the glass. Momentum being ***********, failed to issue the authorization, and had to be reminded by the panel beater with a second email, that was sent on the 6th of April 2023, to remind Momentum about the pending authorization, this is after the panel beater tried numerous times to contact the claims department over the phone.

Authorization was only given to a glass company on the day I was supposed to collect the car (06/04/2023). A confirmation of authorization was given by the glass company on 06/04/2023, and they confirmed that the glass can only be fitted after 2 months as HAVAL doesn't have the glass in the country, and have put the glass on back order.

I raised the inconvenience caused by Momentum to the claim's department on the 11th of April 2023, and demanded a courtesy car. I was told by the claim's department's manager that the only thing disappointingly Momentum can do is to reduce my excess from R3000 to R1500, because my policy agreement does not have a car hire, which I do not understand and agree with because this is about correcting the error they have made, with their resources not mine?