Hi thanks again everyone for the comments.
Went in today to go over the bike with someone and turns out itll only be about £150 which is far better than what they said last night. They were planning on repairing everthing even if it had the tiniest of scratches. Now theyre only going to replace the mirrow and get a new brake lever for it.
I still dont know how long it will take to get it back but it is definitely annoying not being able to use it.