Engine Light

I have had a very bad experience with Budget insurance, my vehicle was Hijacked recently, the process was very smooth and approval was done quick however my vehicle came back with an Engine light and they refuse to fix it saying that it is not related to the hijacking while the vehicle was hijacked without an engine light and came back with it, my vehicle is at their workshop and apparently i have to pay +-5000 for the repairs that i did not authorize, this is very unacceptable as i can't have my vehicle back because i can't pay for something i did not authorize, without proper report.

i have been without a vehicle for 7 days and i can't anyone to give me proper feedback from the insurance. My policy number is ***