bad service

i bought 2 wrapsta boxes and a streetwise bucket for 1, the lady (unfortunately i didn't get her name) who packs and distributes the food gave me only the wrapsta boxes, when i told her that i also bought the bucket for 1 she shouted at me and accused me of lying in front of all the other customers. I gave her my slip to show her and she still continued embarrassing me saying it's not there. It was not until the cashier who served me intervened and told her that she did in fact enter it and showed it to her on the slip that she packed it in... i didn't care that she made mistake as it happens that she might have really not seen it, it's the audacity to embarrass, shout and undermine me and not even apologize...