Vodacom
Contract is NEVER what it seems

Got a contract and phone with Vodacom recently. Smart Light contract which means R169 / month incl. 7s minutes off peak, 100 MB Data, 100 SMS's / month
As I used WIFI at home and at work my data will never exceed this 100 MB
I understand there are hidden costs with the first invoice... R500 including all kind of admin and once off costs.
That was obvious and I understand.
Now the first "normal" invoice there are already costs for Data, SMS and phonecalls... NOW WHERE ARE THOSE COMING FROM? Aren't they supposed to be included in the R169?
Like all cellphone suppliers... this is where the dailight starts allready!

Vodacom... make sure I pay R169 per month as the contract says... I never exceed the amount of phonecalls SMS's or Data in 1 month. (this month my data was never more than 20 MB) how can I be charged for this?
The extra amount was about R 140 extra on top of the contract fee of R 169 which is in the contract.