Worst service ever

Never buy a device online from vodacom. I ordere a new phone samsung note 4 from vodacom online as they promised speedy service on the 8th of May. They delivered the unit to the wrong adress on the 11th and tried again on the 12th to which i needed to make arrangements to get to that adress and collect the phone. Used the device for 3 days and had a network problem where they informed me to do a sim swop. This cost me meoney and a 48 hrs delay. This still did not resolve the problem. I was then informed that i need to have setting changed which also did not help. By the 25th of may is could not handle the problem anymore and requested a swop out as the rest did not work. I was informed that they would send me a new unit and pick up the faulty one withing a week or so. The 8th of june i have not heard anything back and needed to phone them three to four times a day. Each day they refer me to a new person to make the same statements as the one before. Ive asked to have all my contracts cancelled and they agreed but now they seem to want to go back on their word. I do not know what my next step is.