Continuously unsatisfying service

I plave my order at 13H29 after 20 minutes I realize poeple who came after me left .O went to the counter and ask they say they are busy preparing my order ( .I told them my order number doesn't show on the screen .I went the second time to ask and only then they ask for my receipt coz it doesn't show on the secreen .I am nit happy with their service and it's second time similar thing happens .