Full Refund
I went to buy a semi-rare video game (Final Fantasy Tactics, before it became a Greatest Hit). Met this girl in a Wendy’s parking lot, she gave me the CD case. I opened it and it was empty. I demanded my $20 back, she looked at me and said if I did anything other than leave, she would lie and say I assaulted her. I pulled out my phone and started to pretend to record her (my cell at the time had no camera) and she started stumbling around, pretending I had attacked her.
After a minute of this silliness, our eyes met and I think she realized how ridiculous this was getting and gave me my money back.