Upgraded contract and received a faulty Phone

I upgraded my contract today the 20th February 2015 and received a blackeberry 9720 phone in the package. I came home and the phone wont charge and periodically freezes. When upgrading the contract the consultant who assisted me said we had a 7 day exchange and there after a repairs Guarantee where it would be repaired off site. I immediately went back to the store and took the phone and asked for an exchange. I paid the R150 admin fee as requested and was expecting the phone to be replaced as I was informed by the consultant. Issac refused to give me an exchange phone and said it had to be sent off site for repairs by a technician. I then said if that is the case I do not want a repaired phone as it should be a brand new phone to then cancel the upgrade. Issac said it was possible to cancel the upgrade but refused to give me back my R150.00 admin fee. I find this totally unacceptable as this should be a brand new phone and I should have no issues in this regard. Issac's unhelpful attitude for a manager is shocking. I can understand if it was outside the 7 day exchange period but it was the same day. Please assist urgently or i will cancel the contract