sellling cellphone contract

on 30 January 2015 Innocent from FNB Cellphone sales phoned me and offered me a special on Cellc contract in terms of which, I was going to get Samsung Nano tend and a Nokia phone. I specifically told the consultant that I don't want a Samsung Mini I want the bigger version. and I was promised the bigger version. 10 days later a Samsung mini fone was delivered and I was told the nokia was out of stock. I immediately contacted FNB and informed them of my displeasure and requested them to cancel the contract and collect the fone. The fone was collected within 7 days. At the end of the month Cellc started debiting my account for the cost of the contract. I phoned FNB and was just given a Cellc number to contact to cancel the contract. I never spoke to Cellc it was FNB who arranged the whole thing and I feel that they should get me out of this mess because I am struggling to get through to Cellc and they have been debiting my account since February 2015. I want a refund of all the debits that Cellc have made from my account, and the contract to be cancelled immediately!!!!