Honestly @patriciar49, I have to disagree on this one. A lot of stores actually do accept returns on gently worn items if something's wrong with them. It really depends on their specific return policy.
Have you actually tried returning worn stuff though? I know from experience that Target and Nordstrom have let me return things I wore once that didn't work out. Their policies say "final sale" on some things but if the tags are still attached and there's a clear defect, they pretty much always take it back.