Do you mean they don't insert into the lock, or do you mean they insert but won't turn, or perhaps do you mean they insert and turn but don't unlock?
I ask because if you mean the one of the first two, then there is indeed a problem, but if you mean the last, the problem is not the keys. Furthermore, both of the two locks on the door use the same key, the other key is for hatches elsewhere, not the entry door.
The two door locks that use the same key do not operate the same way, either. One of them has two positions, and locks the door handle, the other one does not lock the door handle, but runs a dead bolt, and has three positions.
I am not trying to pick a fight here, or suggest that you do not know how these work, but something about the dealer saying they tested the keys and your saying you tried combinations of keys suggested you just might not know how they worked. Having myself fallen victim to my own misunderstanding of things mechanical in the past and the frustration that causes. . . .
Anyway, if I am wrong here I apologize. But if you can stick one key in either lock and turn it, and one of the locks actually frees up the handle, then you have the right key. You just need to use that same key in the other lock too, and one position of the three will retract the deadbolt and let you in.