Damaged laptop after replacing the fan

I sent my laptop to HP for them to replace my fan, thinking they would be the best people to do the job. After it was returned I noticed that the hinges were not working properly anymore, and it turned out that they were broken by HP while they were replacing the fan. I sent it back to them to fix the hinges, but now after waiting for 8 weeks they still haven't returned it. I feel that this is absolutely unacceptable as I need my laptop urgently.