Very, very poor and unreasonable customer service from Vodacom

An ongoing saga. Vodacom made a mistake when I requested an online upgrade on existing contracts by creating new contracts - they do not want to admit the mistake. They now request that I must return the devices advertised (Black Friday offers) and start a new process of upgrading. How can anyone trust them to do it correct this time? My advice to people out there is to stay away from Vodacom, their customer service sucks and their motto is "The customer is always wrong and Vodacom is always right".