Agreement on upgrade changes overnight.

Hi, I have been a Vodacom customer for over 10 years- with an average spend per month of R2300. Since I just had a baby earlier this year, I wanted to save and lower my cellphone costs but I had found out from a colleague that if you spend R1100+ on a line you qualify for an early upgrade. On his advice I contacted vodacom in February (***) and was told that in December the amount for average spend had gone up to R1300 (of which I still qualified for) - but I was told I would have to wait until May (this year) before I could upgrade prematurely- so I waited. Today I called their upgrade centre for the early upgrade and now Vodacom is singing a different tune. I was told that 6 months ago (before I was told to call back in May) they had cancelled this option. I am so dissapointed by the conflicting information given by the call centre staff who come across as being uninformed and not on the same page- thereby being ********* to the customer