Their lines may have been down at the time of the transaction. Which may mean it might not actually debit for many weeks. I work in a bank and have seen some people get a surprise when it debits- and usually overdraws the account too. So make sure you keep the funds available in your account for when the store reinput the transaction- it can (and I have seen) take sometimes 6-8 weeks to debit but most of the time it is within a week or so (especially with bigger companies). I can imagine how frustrating and inconvenient it is.