Invalid contract- No contract agreement-unathorise

Last year in August 2014 ,a consultant from fnb called me on my cell phone, he said since I have been buying lot of airtime via cell phone banking, fnb will like to reward me for buying airtime through cell phone banking and they would like to reward me with free airtime and phone,three weeks later I got a cell c sim card, which I never activated, and a week later I got a galaxy fame lite phone from fnb, I was happy with everything up until cell c started deducting money (R125) from my account since November 2014, I was ****** off, becuase I don't have any contract will cell c nor did I buy anything from cell, I called cell c and they told me I have a 24 months contract with them and the sim card was registered.I never agree for any contract with fnb or cell c ,the fnb consultant offered me free airtime and a galaxy fame lite phone, I don't even use cell c, I use mtn .FNB cellphone banking is so *********** ,this is unacceptable poor service from fnb and cell c !!<br>