Misinformation of Promotion

My fiance has just taken out a contract for an iPhone 6 from the Telkom store in Adderley Street. It is on the R499 a month deal. When we were discussing this with the sales rep we were advised that we would receive free unlimited data until the end of March 2015. Upon updating my software on the new handset via the iTunes desktop, we discovered that our laptop had connected to the personal hotspot despite having a full WiFi connection and not asking us to verify the connection between the laptop and the iPhone 6. It then proceeded to use up all of my data