Dishonest business practices

I've been a vodacom contract customer with 3 top tier contracts for almost 10 years. Last year someone at vodacom called my to do a migration to a new package for extra data.i specifically asked this person, will this affect my upgrade date in anyway and she clearly answered NO. Fast forward to wanting to upgrade, I'm advised that i have to wait another 12 months due to the migration. After calling numerous departments and explaining this, they acknowledge that the agent has **** but nothing can be done. I even requested the call recording to prove this but all they say is that even if she did lie nothing can be done. What pathetic unhonest business is this from such a large company? Someone help!