Terrible service

On the 22 of August 2017 I had ordered a king value chicken meal. Last week when I was at the store I had requested the staff to change the mayo to the chilli cheese sauce and this was done with no problem. Today when I had made the same request they said they were unable to as it is a promotion. What is the difference from today and last week. There seems to be new staff that do not even try to help, and then I still got my order late as two people that were before me got their orders first. When the manager Nhlanhla was called he did not even try to resolve the issue and instead of came with other problems and no solution. This is a new store and with the way things are going they will lose customers very fast. The lady at the till I dealt with was Saney and all she could say is its new staff but how does that become my problem?