This is actually not that uncommon depending on how the merchant processes their transactions. Typically you'll see the transaction in a pending status on your account, then it will drop off. This causes the funds to be released back into your account and there's no sign of the transaction.
Then 2-3 days later, you'll see the transaction again, this time it will skip the pending phase and be posted to your account.
Can't tell you how much confusion this causes.
Basically what happens is the merchant/vendor will do what's known as an authorization hold on the funds. They do this to make sure you have the funds available at the time of purchase. Once they get the authorization, they will process the order (or credit your account if it's a bill you're paying) but won't submit the actual purchase until a few days later.
This causes the transaction to appear, disappear, then reappear on your account.
So, for that few days in between, it looks like you have more in your account than you really do.
This is why you need to keep a record of your transactions. The only way to be 100 percent accurate is to keep a check register and record everything you buy, subtracting from your balance as you go. Online banking and phone banking are just tools to verify what you have written down, to see if stuff has cleared yet.
If you couldn't tell, I work for a bank. I've seen this countless times. Please remember it's your responsibility to keep track of your money. The bank is just a clearing house for your transactions. Also keep in mind that you're the only one who knows what you spent, when, where, and how much. Your bank only finds out after the fact. Please guys/gals - write it down. Fees are too high to rely on someone else's records.
