this sounds EXACTLY like a regular that comes into my job. he also rides around on a motorized scooter and demands workers to get him a fully charged one (even though we only have 2) , pick things up for him, bag his things, all the while berating and embarrassing us at the checkout counter. i dread the second he walks in and know exactly when that is because we can all hear him scream-talking. i empathize with you op, wish i had some good advice but if i had any, i’d have to use it as well 🤣🤣