That was relevent...
Recently our local Delivery service has started withholding change. Basically in our area we have one delivery service who do all the local restaurants and food places. And if you order say $25 in food and pay with $30 they will just walk away without handing over your $5 change. Now if it is 5 cents i would tell them to keep it, i mean who needs an extra 5 cents in their wallets - but they are withholding anything up to $10 at a time!
And the delivery drivers always get their noses out of joint when i demand my change back (nicely request actualy) and i now try to always pay with exact change. And i even had one driver ask "what, no tip?".
But do i have grounds here to call the delivery service and complain? It isnt the same driver every time, it is all different ones so they have obviously cottoned on that this scam is working.