Billed my credit card I reservered the room under....

Billed my credit card I reservered the room under.
Then they billed the whole stay under my friend's debit card and told her only for incidentals not the reservation. Imagine the surprise on their bank account. Took a week to get this straightened out with the hotel staff and get the money back in her bank account even after they billed my credit card immediately after. I'm not sure their business practices are legal for charging the same room on 2 different cards at the same time.