And hubby doesn't suffer from the same problems for some reason?
The credit slip charge is only if you did in fact sign it. If it turns out to be a false charge then you don't get charged the $500 for questioning it.
It is one of the things that irritates me about HK that companies are allowed to put names on their credit card transactions which are completely different from the trading name which the customer knows them by. I quite often have similar questions when reconciling my statement, so I try to keep all of my sales slips to help in the process.