Vodacom fibi is doing me wrong

Iyoooo vodacom introduced their contract fibi service for 800 then suddenly I saw my self paying more than 1200 when I asked I was told that contract was finished but no one contacted me and give options,instead they decided to do what they like,from february I tried to migrate from that high amount to law amout,I chose the option of paying 500 but even today iam told stories of this and that,I think they are a ****,instead of the paying me back the money for upgrading without my concern,iam hearing more stories,iam done