When I checked into a hotel in Vancouver, I swiped my credit card and paid the deposit. Why didn't I return the deposit or invoice when I checked out?

The credit card deposit is like this. That's pre-authorization, that is, let the hotel freeze your funds through the bank, and freeze as much as you spend, but your money is still on your card, just frozen. When you check out, the hotel staff can manually enter the pre-authorization for you. For example, how much money you spend will be transferred to the hotel card, and the remaining deposit will still be on your card. There is no receipt or anything like that, just a small card slip of a credit card machine. It often happens that the hotel has completed the pre-authorization but the bank has not received the unfreezing information. This is generally a system problem. Many people go to the bank to complain, but there is no way to solve it. If there is, don't worry, the pre-authorization will be automatically unfrozen after 30 days.