False advert and Phone calls after online upgrade without any verification

On 9 November I upgraded my cell phone contract online (it was due for an upgrade). I received order number#***, a day later I was phoned by a strange number claiming to be Vodacom and wanted me to confirm personal information. I refused to confirm any information as there was no way for me to confirm who they are. They refused to give the address they have. Today when I followed up with vodacom they said my order is cancelled, a lady reinstated it but then all of a sudden said that the theft cover is only for 2 months and no buds included. The offer clearly states 24 months cover with buds and I have a screenshot of this. She refused this offer. Seriously don't understand why there is online offers and functions if vodacom is not honouring it?