Incorrect order received multiple times

I ordered a meal today on Mr D food app. I placed an order by fat cake city noordwyk in Midrand and once again they got my order incorrect. This is now the third time I order from them and they get the order wrong. I ordered a crunchy chicken burger with a granidilla flavored cold drink today but I received an apple flavored cold drink. When I phoned to enquire as to why they said the manager is unavailable and they can't assist. In the past I used to order a pineapple burger from them expecting the pineapple on the burger but they never added the pineapple. Only after complaining to them they got my order right but I had to remind them about the pineapple. This happened twice to me at which point I decided to stop ordering the burger as I would just frustrate myself due to their neglagince.