Bad customer service

Had a bed experience at Mc Donald sandton city went there to buy 2 plan Sunday only , what I received in a cup was something else the cup was not full when I enquire I was told that that’s the way it’s supposed to be . Surprising that the other one was full in the cup , I enquired about the ice cream thinking they have made a mistake but no the response I got from the shift manager was attitude , didn’t like how she responded because I’m a buyer there I buy from breakfast to lunch so I know when a product it’s not the same as normally so disappointed of the service I received