Pannacotta - I've never done it myself since I have no patience for sales queues but I'm sure some people with more time on their hands do . It's probably fraud of some type but I've returned things to shops that I just changed my mind on (not Christmas presents).
That reminds me, I must take back some jeans I foolishly didn't try on the other day. Size 14 and I could have got my dd in there with me with room to spare for a few more kids ! 14s.... more like 18s....!