Debit card transactions are supposed to be instantaneous. Occasionally, transactions disappear into cyberspace, sometimes forever, sometimes showing up much later. You could take this up with the retailer concerned or your bank, but you may find it more trouble than it's worth, and may even finish being debited twice. Most people would continue to keep their heads down.
cheques are now valid for 3 years!! and can be cashed BEFORE he date on them too. Gone are days of post-dated cheques I fear.
Got this info from the Halifax just a few months ago as I had hear the 6mth limit had been amended.
Cheques are definitely still valid for 6 months once dated and payments on your debit card have no limit of time.
Contrary to previous advice, don't take this up with the bank - speak to the retailer.
Bank of Stevie :-)
Normally it shows up the next day as most retailers put it straight through on the machine direct to your bank (unless they take your card details and charge you on dispatch of goods but they wouldn't swipe it while you were there in that case). I think you're not going to have to pay for whatever it was!