Love the way you worked this against HR. I had a situation kind of like yours once where we got a per diem daily for a hotel and one meal. The company let us keep the leftover money from the per diem until they hired a new manager that insisted we turn in the extra (it wasn't much maybe $5-25). Fine, we all started getting more expensive hotel rooms and spending the rest on food using every cent they gave us. . After about 2 years the guy who made us turn in the leftover money left and we went back to being able to keep the extra money.