Bad behavior from cashier

Recently have been at cash crusader potchefstroom and got helped from the guy who works for sale department helped me nicely but when I came to cashier asked about warranty she was very rude and told me that are you stupid bcoz you should ask the person who helping you for the warranty then decided to leave the stuff there don't know the cashier was on durgs so she was less for the drugs or whatever but was very bad behavior from her