Speaking from direct experience with the card companies and merchant services (processors) working with the nightclub industry, the vendor will win a chargeback claim if (1) they have a copy of the drivers license, (2) a copy of the credit card, and (3) a copy of a signed receipt. If they have that trifecta, it doesn't matter what the "wanker" claims.
So for all of you using credit cards at AMP's, just know that they are likely scanning your credit card and drivers license into a .pdf file into a laptop in the back of house.
IF they charge you more, yes. And AMEX is notoriously difficult for vendors to fight chargeback claims. That said, if they have the drivers license copy, the credit card copy, and the signed credit card receipt, even AMEX will have to honor the charge.