Is a restaurant not permitting the use of an expired Gilt City coupon? Is a merchant not letting you redeem the remainder of your voucher for cash? Enter VoucherComplaints.org, a website that comes courtesy of Ben Edelman, an assistant professor at Harvard Business School. The site asks simple questions about your voucher problems and generates letters citing relevant state law. The site is a work in progress, partly because state laws are still a work in progress on these issues. New York State law, for example, isn’t entirely clear on the issue of voucher expiration and other issues just yet. But if you’re in Massachusetts and your Groupon has expired, you may be able to redeem it for full face value. Try it out. We’ll call this one a GOOD DEAL.