won a phone buts its on contract billed for it

In the month of May I was contacted from a agent that said that i won a phone and she calling from FNB.<br> Reason been is that I always purchase airtime and data through cellphone banking.<br> Couple of days passed and i was contacted and advise that the device \i won "will be delivered on the 12th of May -what a happy customer I was.<br> Months passed and got bank statements that my account is debited from the little stipend i get supporting 3 children with R1200.00 and still been billed for the \""won device\"".I went to the bank and was advise that its a contract phone that i did not agree for neither app**** or signed for and they said they can do nothing about it i should call Cell c with no assistance at all<br> Contract number:***"