FALSE ADVERTISING

There is a contract advertised on the website for a Hauwei P40 Lite + watch for R429 per month. When I contacted the call center they told me that they did not have stock of the watch. So I contacted the Phoenix branch and they managed to get the watch but they say that the contract is now R579 and there was an error on the website! I contacted the call center again and they now say that they are not responsible for the error! How can they advertise a price and then say its an error, and they still have not removed it from the web site!