I had a hotel double charge me a number of years back. I called the hotel to straighten it out and got some run around. So, I called my bank (USAA) to ask what I should do. They said “do a chargeback and that’ll force them to show documentation”. “Okay, I’d like to chargeback one of the transactions.” “We’ll just do it for both and let them sort it out.” Hotel never responded at all, so the entire stay was free instead of just being the correct amount.