Simple. Get them to repair it.
This is the reason I hate taking my car for any work whatsoever but the last couple of times I've had to take it to the dealer, I've cleaned and polished the car meticulously and asked the person booking it in to inspect it before I leave.
Both times when I've come back to pick it up, its either been straddled across 2 spaces (the spaces are very tight) or parked in a very large bay on its own. They obviously took notice of what I told them.