Something similar happened to me back in Feb. I rented a car for one day from the HLE I rent from every week had the pending charge when I picked i up the car, returned it and put the keys in the drop box, the next day I never got the receipt and the pending charge fell off. My year to date rental number didn't go up after it either and I don't have a record of it in my past rentals. I rent from them every week so they would have said something if there was an issue, its probably just a glitch in your favor.