I had protected my Apple iPhone 3G with ScratchGard. After 2 weeks of usage, it had black marks imprinted on it. I was afraid that the screen was affected. So, I removed the scratch guard. To my relief, the black marks were on my scratch guard. I got a new one and the same problem persisted after two weeks of usage- so this was not a one off problem.I mailed the ScratchGard team (twice) with the screenshots of the problem in their product. I did not hope that I would get any response but I did get a reply from their Sales team to scan and send them the invoice.  After completing the formalities they send me 2 scratch guards (as I had bought two) and all this was done within a span of 2 days. Amazing! As per their request, I have sent the defective product back to them so that they can check if it is a counterfeit product or if there is some issue with it.Cheers to their entire team for their quick and effective response.