Hyundai Motor India — replaced part without informing

Dear sir,
My car was flooded and was at hyundai service centre for six months. Because i was fighting with insurance company for total loss. At last i got some amount from insurance company which was disbursed to the financer and i got the flooded car back as it is. The main problem is that when i went to take my car i found that my car bonet was replaced without informing me and i don't know how many parts has been replaced. The question is that how can we trust on the authorised service centre.