Ethel M Botanical Cactus Gardens

We paid for parking one night in Flamingo Self Park which was $20.00 and was placed on our room key. When wanting to get out of garage in the morning to continue our vacation we were charged another $20.00 card said no funds found. Called the hotel and was tranfered to billing and was told since we tapped our credit card we needed the security number. Well how does that happen? We do not have wallet on our phones and are never given a different security code. Was told we cannot be refunded without. Not very helpful at all. I want my $20.00 refunded somehow!