Manger siding with his staff

On Saturday the 26th of July I went to Hungry Lion Pier14 to buy the special that was on promotion. I got there before 11:00 and was standing in line waiting to be served. The lady infront of me was served and I was next . As I approached the till the cashier walks away from the till saying she is going to get change, not even asking me if I'm here for the special knowing it's almost 11:00 . When she came back I told her that I would like the special and she simply just told me that it's pass 11:00 and that I would not be able to get the promotional deal. I then asked to see the manager. The manager then arrived at the till and asked me what the problem. I explained to him that I was there before 11:00 and that she walked away from the till. He then told me that there was nothing he could do without even an apology. The branch in Pier 14 has the worst service in the whole of Port Elizabeth they even cause late delivery for Mr D drivers because I have watched them not too long ago. They have no customer service in them at all for their walk in customers as well. I would like that branch to be investigated because I have never had such bad service and I have been silent about this branch for to long. I live close by so that branch is the closest one from my house.