Extremely poor customer service

I app**** for a contract at vodacom and it was approved and the order was confirmed. I later got a message saying that the device was not in stock and that it'll take about a month for it to be delivered. I then requested to change the device to any available device and now they telling me that I don't qualify. Now that I want to take the previous order I'm being taken from department to department with no help or solution whatsoever. So disappointing 😡😠