FWIW, I'm busy like everyone else and didn't get around to returning my headphones till last fall. I attempted return to Verizon who rejected the return due to the lapse in time. I had an email from Cartera to return to them for a refund with no timeframe. I mailed the package by trackable means last fall and promptly forgot all about it. Cartera of course did nothing.
I emailed them the order and tracking details a week or so ago. I included their original case specifying they would accept the return. I received a begrudging letter from their general counsel saying they were cutting me a check.
In case there are any other procrastinators out there.