Staff are not very well trained. I tried to insist that I had already prepaid my reservation, however, the staff refused this explanation and proceeded to demand payment again. I provided this, as I planned to immediately dispute the transaction with the card issuer, only for the hotel staff to finally realise their mistake after taking payment for a second time. I then had to be refunded (which, by the way, takes 5-7 working days to process). Not a big deal normally, but it took 35 minutes to get to that point and not even a "sorry" from the staff. I also now have a 400 euro block on my card for the next week. Never again, holiday inn.