I think I was charged more than once
If you attempted to pay via credit card and were declined for any reason, and then you proceeded to pay successfully, your credit card company may show two charges. This is only temporary as a void will be posted to your card within a couple of days.
Sometimes when a card is declined, the credit card company can only see part of the transaction. A void will be posted to the account and you will only be charged once. We will never charge you twice for the same posting.