What is the law relating to liability of a company when a product damages property it was intended to protect?

[felabeorbt]

What does the law say about this? For example, if I purchase an expensive case for a mobile device and after a week of use, that case has made noticeable wear marks on the device, what is the companies liability? Will a limited warranty waive their responsibility even if the product was found to be defective? Any statutes relating would be greatly appreciated