Incorrect orders delivered

For just under a year now, we have been ordering food from the Nandos on Pritchard Street in Johannesburg and every time we order they always deliver the incorrect items. One would order an item in lemon and herb but they would deliver in mild or hot. This gas been happening for 10 months now and every time we would send the orders back for correction. Sometimes they get the orders wrong even on the second delivery. I have had it with their very very very bad service that my team and I receive from that shop all the time!!!!!! The attitude from the staff also leaves a lot to be desired. The staff is always back chatting on us every time we query an order. This makes it such a mission to get our orders corrected. What's worse is that they get the order wrong even if you're ordering one item, sometimes even when you're not placing the order by telephone.