How dare you to tell a customer to respect you!!!

I went and bought myself some droe wors, went to the cashier who always helps me and is always friendly, as i was paying the supervisor came up to her and asked in front of me and other customers, Where is the Change?, is it in your Red Bag, did you check your red bag? did you ***** it?, I then asked him where is the Owner and he showed me to a \Frank"who said he is the owner"