Eh, I had a weekend reward at MIA where upon returning the car the alleys were pandemonium and we were running a bit late. I left the car and got on my flight. I've done this before and the receipt has always showed up within an hour. What could go wrong?

Couple days later I get a receipt emailed. Turns out they charged me for three extra days on a "free" rental. The first person I called basically accused me of lying and the exchange got a little heated. He refused to believe that I was in Cincinnatti on the day he claimed I returned the car.

I hung up, calmed down, got another agent who took care of everything, at least that's what she said she'd do.

Still waiting for the credit to my AmEx to show up... but now I will no longer just leave the car without getting it checked in.