Dishonest upgrade marketing by online telemarketers and bills not as per quotes given.

I have 6 data contracts with Vodacom 3 done seperately and another 3 at the same time. When it came to upgrading the 3 done at same time and same price had 3 different prices quoted for the upgrade, which i contested as its the same contract x 3. I now get a bill for the upgrade which is not what i agreed to and another R113 added for 2G monthly additional data which i did not ask for since i upgraded from 5G to 20G, so why would i still add 2G extra? Vodacom is marketing their upgrades with misinformation and total dishonesty. you never get your quote untill you get billed and then its not what you agreed with.