False advertising

So I went to Mcdonalds in Pritchard street in Johannesburg cbd to order food. I ordered chicken nuggets and the chicken meal. I waited almost 30 minutes for my order. Guess what- I had to leave there without my food. I was with my friend who bought another meal and she got hers in 10 minutes. So why is McDonalds advertising something they don't have (chicken)? I wasted so much time. If you had to ask me, I wouldn't recommend people buying there ever... especially if it has to do with chicken.