wheel - 1:33 pm on Apr 28, 2010 (gmt 0)
We bought $100 of chocolate gift baskets at Christmas this year and my bank card didn't work so we threw the charge on a cc. The charge never appeared, the store screwed up.
We went back two months later when it became apparent from our statements that we weren't going to be charged (I did make them confirm with their receipts for the day that we hadn't paid cash or something like that and I'd simply forgotten). The store was very happy, gave us some more chocolate.
So you should let them know, if only because it may be an opportunity for free chocolate :).