Jet misrepresenting MTN

On 13/05/2015 I purchased a Samsung handset and 3 days later when I tried to charge it nothing happened. I then returned the handset to the Rustenburg branch(where I bought it) for exchange on the 19/05/2015. When I got there their cell-phone consultant put it on a charger and it miraculously started charging again. I then explained to her that when I tried to charge it at home it did not charge at all but the consultant insisted there was nothing wrong with the phone. I then insisted she rather book it in for assessment as I was not comfortable to take it back again just in case it does not charge again a few days later. She then told me that should she book it in for assessment I will be liable for R330 assessment fee. I then asked her as to the '7 days exchange period' as per their 'Terms and Conditions' and she called their 'Mtn Technician' who instructed her not to exchange the handset. I then called Mtn helpline and they confirmed that I was supposed to get a new handset as per 'Terms and Condition's that Jet and I have signed for. Jet I don't really have time to play, that phone is about 'R1100' and I would not have wasted petrol and time if there was nothing wrong with it.