Poor advice and no courtesy

The turnaround time for my repair claim is 3-4 months because their service providers do not have parts. I took a car hire for a month thinking this will be sufficient and now I am stranded without a vehicle for 3 months and when I called the service provider today he says that the assessor told him he does not have an estimated time of completion and could be 4 months. The vehicle manufacturer has a backorder on parts is an unacceptable excuse to wait 3-4 months for a minor mechanical repair. As an insurance company that has insured other vehicles from the same manufacturer should have the courtesy to advise me, as a client, that there are backorders with the vehicle manufacturer and advised on options for an appropriate car rental cover instead of just leaving me stranded without a vehicle or any courtesy for the position I am in! The call centre agent says this is the first time she heard about the waiting period for parts and cut the call and did not even have the courtesy call back.