On my very first night in Cuba, as I tried to check in, the lady at the Sanctuary check-in desk tried to scam me out of more than $600, the cost of my stay. She started by claiming that my credit card had been denied for this booking, even though I knew the payment had gone through because I had paid the card bill before I left Canada. When I brought this up, she kept insisting that my card had been denied and that I would have to pay her in cash before I could access my room. She tried to prove this with a printed email message with my room details, and a single scribbled word in pen "denied". However, she let slip that she thought I had done the reservation with Booking.com, at which point I knew she was lying because I had obviously done it with Expedia.
Luckily, I had a printed copy of my Expedia itinerary, which I then showed to her, after which she got flustered and eventually let me check in, but not before trying one last ditch attempt to keep the original printed itinerary with her in the office "to show her manager tomorrow morning", but she declined to photocopy it, meaning I would be voluntarily giving up my proof of payment to her. Obviously, I did not let her keep it, at which point she seemed to give up on the scam. When I checked out a few days later, no one mentioned anything about outstanding payments, which proves that this lady was out to scam an unsuspecting first-time young visitor to Cuba. I was lucky I had proof - others may not be.