I bought a Magic the Gathering display box today with cards from the new edition Innistrad. Unfortunately one of the cards in a booster pack was damaged. It is not just a simple scratch - one corner is bent and a small part of the card is missing. According to different trading platforms this card would be worth about 6 Dollars minimum in mint condition. So it is not really expensive but also not totally worthless.
What can I do about this? Can I obtain a replacement card from the producer (WotC) or from the store I bought it from? How can I prove that the card was damaged when I opened the booster pack? I am sure I am not the first person who got a damaged card from a booster pack. How are such issues usually handled?