Agitated with your TAT of parts ordering

I was involved in a car accident in June , it is almost two months now my car been sitting in a panel beater because panel beater is waiting for KIA to ship parts . How long should I wait 4 months for parts to be delayed , do you consider the logistics that I need to use the car for , as my insurer provided me with accident courtesy car which is only last for 30 days . And my insurer has paid the panel beater now I am still remaining without a car , what if the panel beater exchange parts not my car battery next is going to give me problem cause it stayed way too long at panel beater . I would rather go in and tow my car as it will be under my supervision . This is just a daunting situation one should experience when the car is still brand new