I know its frustrating to not get a receipt when you want one but I think more and more places are going that route (less paper, less expense). I am thinking there are so many times these days that your check is your receipt, your statement is your receipt, etc.
Just think now of all the things that automatically are deducted from my checking account! I know right now we have several insurance payments, a loan payment, aol, our newspaper, and I am sure more taken out and the receipt is our checking account statement the next month.
Anyway I am thinking its just more a sign of the times (of course also a sign of the times is these lengthly waits when calling for service places too).
It sounds like you did get your passes though so that is good - hope you enjoy your trip - whenever it is (mine is coming up soon and I can hardly wait!)
Liz