The age old saying is the customer is always right.  But that saying doesn't apply to tax preparation.  Tell them that if they wanted the full exclusion they should never have rented the place.  If they don't like that answer, tell them that they are free to leave and try to find someone that will prepare an incorrect return for them if that is what they really want.  Also tell them that cell 103 has the best view in their local federal prison.