Non existent servce from Nandos drive thru

Service simply does not exist at this "fast-food" place. At the ordering window, although open for business there was nobody serving even though they saw me waiting - I could see them watching me. As I was driving away, suddenly another serving window opened and the server shouted at me to stop, which I did. She took my order and I was directed to the parking lot where I waited for 15 minutes for my order. This is not the first time it has happened to me at this drive thru but will certainly be the last time. McDonald is across the road, think I'll give them a try next time.