2.5 month old Mac computer, already broken?!?!

I think that the title says it all. VERY frustrating. I lost my computer for 5 days (it had to happen on a weekend, to add insult to injury). Something with the hard-drive, which they claimed was scratched. Have you been using this on a corner or at any angle? Um, no, I am pretty sure I was sold a defective one....So was not very happy with Apple with this one, but it is back and running smoothly for now. Fingers crossed!