Vodacom isnt assisting me correctly with online upgrade

On 7th December 2017 i placed an upgrade order on Vodacom's website. I received a confirmation of my order via email. Vodacom should have followed up with a call to confirm my order and delivery date and address. On Monday 11 December 2017 i still did not receive any calls from Vodacom, I then called into their upgrades department. They told me my order was cancelled because Vodacom tried to call me 3 times (which they did not) and then cancelled my order. Since Monday I have been calling into the call centre with no success as the agents either tell me i must go into the store or the calls gets cut, and you cant get back to the same agent!! Yesterday morning i spoke to a team leader in the upgrades call centre and he flagged my order as priority, they were meant to call me yesterday afternoon but I havent received any calls yet. I cant go to the store to do my upgrade as the stores dont have any stock of the phone i want, this is all getting very frustrated!!! If Vodacom does not sort this out asap i will be changing my cellphone network!! I've had bad experiences with Vodacom before but this has been the worst! Its a simple upgrade!!!