Online "up"grade horror

My contract has come to an end on 23 November 2018 (which I was aware of way in advance), so I have done an upgrade online on 22 October 2018. Since then Vodacom has dispatched my delivery via RAM couriers twice - both times providing them an incorrect address and an incorrect contact number for me. HOW DO YOU DO THAT? ALL MY INFO IS RIGHT THERE ON YOUR SYSTEM. Furthermore, it is now 29 November 2018, and I am still not on my new contract, being billed now on a month-to-month basis for the old contract. When I phone the call center, I am promised that everything is fixed and sorted, just so that I can find out later it was not the case. Also - the amount quoted the last time over the phone is higher than the amount I have done the upgrade for (for which I also have a confirmation letter). HOW DO YOU CHANGE THE TERMS OF THE CONTRACT WITHOUT CONTACTING ME. THIS IS UNACCEPTABLE!