Why is swopping an order at Cell C so difficult?

Hi, Cell C called me on the 07/05/2019 and offered me an upgrade on my current contract with them. I accepted their offer because it was a good deal. I later realised that the model that I selected was not the model that I want and I called them on the 09/05/2019 to try and cancel the current order and place another order for the model that I wanted. I was put on hold for more than 5 times for 20 minutes at a time. I finally got through to someone on the 11/05/2019 who said that me order would be cancelled and that I would hear back from them in the week. I have not received a response yet so I called them again today. I spoke to Themba who assured me that my order would be cancelled and he transferred me to another department to place another order. I got through to someone else who hung up on me so I called back. I got through to Jennifer who informed me that she would call me back in 5 minutes. I am still waiting..... They are quick to process orders for upgrades but cannot attend to simple order swops... Very bad service!!!!!!!