For Jan 2016 Vodacom debited R482 on my account

On the 26th Vodacom debited R482 on my account instead of R122. When i called to query this I was informed that i had an upgrade on the 12th Dec 2015 which they couldn't even advise which Vodacom store was the upgrade done for an iPhone 6 which i don't even have. To make matters even worse for their own horrible services i was then told that i need to go make an affidavit stating that i have no knowledge of this upgrade. To date i haven't heard anything from anyone regarding the investigations. When i try to contact their number all it does it cuts.