One of many reasons I always keep my receipts and check my bill at the end of a visit.
Some years, I find mistakes, other times its fine.
Not just Disney by any means, have had it happen at Universal and other places as well.
I can corroborate this. Last November I had to make some phone calls to get parking charges removed from my bill as well. Similar situation, we took a black car service to and from the hotel....
I assume anyone that stays on property is automatically charged unless they take the mouse bus. Easy for them to be sure they get every dollar, annoying for us that we have to be inconvenienced to dispute the charge.