Wording changed for Data purchase, horrible service and no protection for their clients!

So after buying 1GB data each month and following the same steps... I see this month it says R100 for 1GB data. Like always I select and push confirm as a normal step to take. When I get a sms saying I purchased 500mb day and 500mb night. I then again go and look and see it says R100 for 1GB data. They have changed the wording to confuse people to send more money over December time as last month this was not the wording on the *111# to buy Data. Monday monring(today I contact Vodacom telling them this is a mistake and I would like to reverse this because it said 1GB which I did not think its 500mb day and 500mb night. They refuse to reverse it and says it cant be done. Why would they change wording no suddenly if it was not to trap clients. My colleague is also angry as this happened to him as well. This is the worse service ever. Also in the middle of the year I had a R7 go off daily on my account fo some or other subscription. This was happening for 3 months. I alwasy wondered why mar airtime goes so quickly. So finally when I had time I phoned Vodacom and them telling me I subscribed to some or other subscription. They spelled me the name(cant remember it now) I googled it and could not even find this name on the internet. Hos is this even possible. Should they not protect their clients with ***** sms coming through. I delete all sms so dont even know how it happened that I subscribed to something like that. So all and all I have just lost so much airtime this year from Vodacom and they are not even willing to correct something as it was them changing wording and trying to catch out people. Absolutely ridiculous service from Vodacom! Told them next year when my contract is over I will cancel with them. The guy with this snotty attitude still refuse to help me says can I give you the cancellation number. No you DONT I have it and why would I cancel now so you just take more money monthly with another NO SERVICE option from you! Horrble servcie VODACOM!!!!!!! Definatly not a customer care line!!!!