Just because it was on sale is no reason to accept a used or defective product. If it was clearly stated that that was why it was on sale that is different. I'd just take it back and they will either give you another one or refund your money. If you get another one, I'd have the clerks unbox it there and check the surfaces. I've had to do that with some Ikea stuff as well. It's a pain, but making two and three trips is also.
Diana