Machines IOI City Mall - Very very rude staff

Went there to buy a backpack. At the cashier, this staff, she's wearing a black scarf was super rude when I asked her if I can make a double check on the backpack. I asked her, "Boleh saya check dulu?" and she goes, "BUKA LAA!! KENAPA TAK BUKA DARI TADI?!?". Girl, you're lucky I don't know your name cause if I know, I'd make sure you're fired right away. What a worst experience! Definitely not going to this outlet again!