I doubt GM will reimburse you since you are having the lock replaced at a non-GM shop. Sorry you are having this difficulty. You might could have gotten GM to replace the lock under the recall, but in order to do so you might have been without the use of the car for some time – maybe months – while you negotiated with them. So getting the lock replaced elsewhere might still be your best option. Be sure to ask the shop to document any indication they find that the inserts are related to the sticky key. And make sure the shop returns the old key and lock to you.