False 3rd Party Call Centre calls

i had a call from ***, on truecaller its shows Veena, so my one account is due for an upgrade soon and she told me they are going to half my account amount i pay each month and give me more data and airtime, i asked her specifically if this is an upgrade and she said NO, she said it for my benefit.

Straight after the call i called Vodacom Upgrade Number and they confirmed that its a upgrade to my upgradeable contract and that's not what i agreed too or asked for. This made me MAD!!!!

In a nutshell these 3rd party call centers must stop tricking the people into stuff like this, if i didn't call to find out i would have been stuck with another 24 month contract i did not agreed or asked for.