Vodacom's Fazwaylah Gertse-Grammer Empty Promises

Two months back i logged a query with vodacom data support center because of my account which was overcharged.I am on data contract for R99 a month.In February 2015.my account was billed R1165.06 instead of R99.Funny enough is that they did send me a message to notification to tell me that my data was running out,i did switch off the device of which it had 10Mb remaining of my allocated data & never used it again.I checked on my vodacom iPhone application & it indicated that i had 10Mb left & my bill was going to be R99.The next morning i checked it was R1165.06.I had also set a limit that if my account had gone over by R50 THEY SHOULD CUT IT OFF.I even took screenshots from my phone app & emailed to the lady Fazwaylah Gertse-Grammer who was dealing with the matter after i logged a complaint with the data support department.She promised to get back to me of which she did only for two days after i logged the query & that was it up to now end of April.Vodacom did debit my account for R1165.06 & i reversed it on my bank account,because it was not in my budget & i cant afford it.Is this legal in South Africa ? I also see several complaints of the same nature & i guess nothing is done.