contract complaint

i took out a contract with Vodacom of R129 / 150 not sure in may 2017 in june I got a bill of R1700 odd which they deducted from my account aswell, for data usage and also being billed for 2handsets which I don't have . I took out for my 4year old daughter the tab is most of the time off and harldy uses it I then queried with Vodacom they told me they billed me bcz that is the amount of data I used n I explained to them that it is not possible they then said they will queire it they called me back n said this is my bill and I have to pay anyway I didn't leave it like that I called again n they waivered the amount I asked y am I being billed fro 2handsets they couldn't tell me y ........they cut my line n telling me that I haven't paid the contract which I gave them authority to do debit order every month ........till today I had no feedback or any explanation as to why they billed me for 2handsets and also data usage of almst 2000 rand and i must say i wont ever take out a contract with Vodacom again