Bad bad service

I am so disappointed and angry with nandos the Glen Shopping. I placed the order at 17h31 they told me it's gonna take 15 minutes. I went back to fetch my order at 18h10 it was not done yet like 39 minutes later And the lady who helped me didn't even apologise. Their manegar pass by I called him explain my situation all he could say is sorry I asked him for the receipt back so that when I sent a complaint I will have the person name who helped he gave it to me knowing that the receipt doesn't show names. The menager was not useful.