Terrible service from upgrades

I did an upgrade about 3 weeks ago and it has been the most terrible 3 weeks because im been sending emails and calling vodacom ever since. The consultants are so desperate for commission that they give incomplete information when upgrading just so they get the incentive. I was not told that if i upgrade before my other contract expires il have to pay for the new device i upgraded to and the old one. I only learnt all this when my statement came. I then sent an email asking for explaination to why my bill was up. They says the rules of the upgrade say i pay for both. I have never had this before.its my 3rd upgrade and this is new to me. Had the consultant told me this ibwould have simply waited for my contract to expire 1st then upgrade. I asked for a recording of the day i did the upgrade but they have been giving a a run around for 3 long weeks.I will not pay my vodacom account until this is resolved.