APPARENT EXCESSIVE DATA USAGE

I upgraded on Friday 15 April. Vodacom sold me a new wifi device with 20gb worth of data. For this month it will obviously only be 10gb (proportionate). I asked my friend for help with the update, back up etc on his wifi as I was unsure how much data it will use. So effectively I only started using the wifi router from Saturday. I did not watch any videos or updated any apps or downloaded anything. When I checked my data usage on Sunday evening it showed I already used 9GB!!!!! Seriously!! That is impossible!! Since it is not my first Iphone I refuse to believe Vodacom's stories about icloud etc! I did not back up my phone and all that settings are off. So Vodacom, this is ****************! Further to this, they confirmed the wifi router's battery will last up to one day. Also untrue! Up to now it only lasted for 3 hours top! That means I won't be able to attend anything without ensuring that the device is plugged in a power point. According to Vodacom I will have to bring it in and it will take 4 days to evaluate the device! So 4 days means 18GB on my phone's bill. So consumers - don't buy into Vodacoms new special!!!