Cash shouldn't be concern because a business like this won't take away your money they will not ruin there name.
My 2 cents
A few people having to miss the flight for medical reasons or any other legitimate refund reason, I doubt there’s gonna be who to talk to there ITS A GROCERY STORE!
You have no cc proof, etc so no recourse against the airline
And bingo name not gonna get ruined if a few people are upset