Bad service

Recently, I went to buy my supper at KFC Kempton park. My order was short. I only released when I got home when its was time to have supper. I then phoned the branched asked to speak to the manager. The lady by Thembekazi said she was the manager. After telling her about my query she called another manager who initially was a manager in-charge. I was very upset I started to scream on the phone as she was wasting my airtime as I had to explain again to Jonny the real manager on what happened. Jonny apologized and promised me that he will compensate me and for that inconveniencing me he will give me more than what I ordered. I told him I won't be coming any time soon, he said it was ok I could come anytime. Last week I went there as I was around the neighborhood. I found another manager by the name of Pheladi which she said Jonny was off and there was nothing written on their communication book by Jonny about the incident. I looked like a stupid. So the question I keep on asking myself, am / are we supposed to open the order, count all the pieces if they are correct number or if the item is the actual item? I mean, who does that? especially on drive thru. You only thinking that things would be more easier and faster. I am very unhappy as the money I bought that food I worked very hard for it. It didn't just fall on the tree. From now on I won't be buying from them, again I have told my friends and my colleagues of the bad service I have received.