The Customer? What about them?

Subway used to have a sign that said something to the effect of "if we don't give you a reciept, the meal is free."

I'm guessing that the Rhodes Scholars who man the counter at Subway weren't feeling the "give every customer a reciept" directive from Subway Corporate, because there is a new sign taped to the cash register now:

"If the cashier doesn't give you a reciept, ASK for one. If they still don't give you a reciept, your meal is free."

So, my question to managment is this: If they won't give me a reciept when I ask for one, why should I believe they'll give me a free sandwich?