I ordered business cards last week. I looked at a preview of my design, and everything looked great. I didn't realize I needed to review the proof to see how it would be printed. I receive my business cards, and one of the images is smudged. I contact customer service, and they send me a copy of the proof and sure enough it's smudged in the proof as well so it was my mistake for not double checking.
They let me correct my design, and sent out new ones for free including shipping. Their customer service was really great, and they were immediately willing to help me with a mistake I had made at no additional cost.