Mistakes while inputting payment information can cause your financial institution to put a HOLD on funds and appear as a charge in your online account view. 95% of all mistakes are due to entering the wrong CVV number from the credit card. This is the 3 digit number on the back of a Mastercard or Visa and on the Front of an AMX. Entering the wrong number will result in your bank putting a hold on the funds, and will show up in your online statement as a charge. This will be released by the bank depending on their policies. THIS IS NOT A CHARGE and it will be released.
You can check to see if the tickets were purchased go to the club's website > Login > My Receipts ticket purchase will be shown in that table.
To find out if this is a valid charge or a hold you will need to contact the financial institution your credit card is issued from.
We hope this helps, if this response is not satisfactory please contact either your Bank or the Comedy Club you are working with.