I want my data back!

On Thursday night I checked my data balance which was 1GB+ & switched my laptop off. Next morning I checked emails for 30 mins & ran out of data-no downloading & all updates are switched off. V said data depleted as I had been connected to the internet - I DID NOT HAVE DATA TO CONNECT and laptop was OFF. How can this happen? Last week I upgraded from a mobile broadband ****le to a Wi-Fi router - they say this uses more data than the non-wi-fi ****le? Leaflet that comes with the device has no info about how to use/charge the router, leave on or switch off surely there is a responsibility to do this? V said I had left the router on which used up all the data - BUT my laptop was off?! So they gave me R100 to buy more data - while converting this to data bundle the R100 disappeared? Another phone call . . . yes they could see it had been used up as I was connected to the internet - I DID NOT HAVE DATA TO CONNECT TO THE INTERNET?! Vodacom have a lot to answer for but there never seems to be a plausible explanation. Is there one?! I wish I had not just got tied in to another 2 year contract as I have had more than a gutful of hopeless non-service from Vodacom.