Premature Upgrade

I contacted Vodacom last year Sep/Oct '14 inquiring about a premature upgrade on my contract and was informed that I do qualify for a premature upgrade but could only do this upgrade in Dec '14 as Dec was the commencement of my 13th month on the contract. I subsequently went to a Vodacom Store in Dec '14to do this upgrade but was informed by the consultant that I could not do this upgrade as he could not access the premature upgrade option on his system. I contacted the call centre to find out what the issue was and then was informed that my contract Start date was in Mar and that I therefore only qualify for the upgrade in Mar '15 as this would be the commencement of my 13th month on the contract. I contact during Mar '15 to be once again informed that I only qualify for an upgrade in Dec '15 my normal upgrade date. I have also been informed that I however now do not qualify for the premature upgrade as business rules that changed in Feb '15! Even though the fact stands that I have made you aware of the intention to prematurely upgrade over 6 months ago. Vodacom set the expectation and cant deliver! It has been an uphill battle the whole month of Mar and I still don't have an ans!