Bought a set of 250 lights in Homestore last year. Stuck them on the tree this evening and they worked fine. Plugged them out for an hour and when I plugged them back in they suddenly weren't working

Has this happened anyone else? If I bring them back at this stage and complain is there any chance they'll replace them? I'm raging! :mad:
(Ps- I know this is probably better suited to the consumer issues board but thought I'd get a better response here)