Bad service

Went to Mr Price Central Park in Bloemfontein and got the worst service , I stood in line to get coke collect my lay-bys which I made last month when I got to the cashier she took the slip and made me wait on the side , I was waiting for more than 30 minutes with no one saying anything when I went to ask the cashier was very rude . I was on my lunch break and I had been there for a long time . I had to leave without receiving my lay-by which I don’t understand what took them so long to look for it as there should be some sort of organising system. I want to cancel my lay-by and get a refund because I don’t tolerate poor customer service