Double debit

I checked in on the 9th of December on my arrival I did mention I did my booking through Booking. Com. I paid the money at the reception and the day I checked out I was debit the same amount again. I then drove back to the hotel were I was told Booking. Com debited my account. I was offered a refund form that says I will get my money with 30 days. This never happened that you get debit after you checked out. People need to check their accounts. They are committing *****.