Costco just gave a full $613.37 refund on a 6-year-old dead Xbox, and the reason is a gap in the return policy the company has left open since 2007. Back in 2007, Costco had a problem. Members were returning 8-year-old TVs right before the Super Bowl, taking full refunds under the lifetime satisfaction guarantee, and upgrading to bigger screens. It was costing the company tens of millions a year. So they wrote a 90-day limit for electronics. Read the list they wrote. Televisions, projectors,…