Premature Upgrade Changes

I phoned Vodacom today to enquire about a premature upgrades.Prior to this call I went and did the research and found that you need to have your contract for 11 months and a spending of R800+ to qualify.I was then told by the call centre operator that I can only do a premature upgrade in the 20th month.This was apparently sent out to the clients two months ago (No record of that).It got confusing at this time..Call centre then put me on hold and later informed me that it it was an immediate affect notice from Vodacom given last month?Down from 2 to 1 month now?I should probably have phoned the 1 hour later and then they would do the upgrade?How is it possible to change the rules and not notify your clients?I have been a longstanding client with Vodacom since 2002 and have done premature upgrade with them during the 13 year period with no issues at all.No wonder I am staring to cancel my contracts with them.Is it more important for Vodacom to take my money for the last 13 years and not look after me?Looking after there back pockets maybe?New sport sponsorship maybe?