Sarcastic staff

This afternoon whilst shopping at your Bluff store, I was utterly disgusted and offended by a staff member of yours. Being extremely busy and short staffed, a cashier was brought on only accepting cards, she proceeded to call out clients from the queue who were using cards. As my turn approached I had to ask if gift cards were acceptable at her till. She said yes and i proceeded. Only to get to her and your supervisor behind her making sarcastic comments saying "bank card, credit card, gift card, birthday cards...as long as it's a card and laughs out to a customer that she was assisting. I am not a dumb, i just needed clarity as to whether my gift card is accepted. Please train your staff on customer etiquette as i also work in retail and the customer is always queen! Her attitude stinks! Please address this as the next time it won't be a pleasant shopping experience for her!!!