If you already signed the credit transaction receipt, you will have to prove to your credit card issuer that they didn't provide agreed service completely; if you didn't sign that receipt, most likely that transaction will be voided unless they have other proof such as voice record to prove you have authorized the transaction...
Normally, if there is a credit transaction issue, the 1st action from the credit card issuer is to ask the merchant for a sale record with authorization record. If the merchant can't provide the info, a charge back process will be proceeded...