bad service

<p>in february this year i upgraded my contract with MTN telephonically and received my handset which is the Samsung S6 edge , a few weeks after i had received my phone it started giving me problems such as the battery wasn't lasting, the phone needed to be charged all the time and when it was on the charger it would get so hot to an extent that i wouldn't be able to touch or use it. for more than 3 weeks i didn't get any feedback on my case and i was without a phone after nearly 4 weeks of not having my phone i was told to go to the store to get a new phone because of their findings when the phone was assessed but when i went to the store i was told to call a number since my upgrade was done over the phone and ask for the person who had upgraded my contract, i didn't find the consultant who had done my upgrade but someone else assisted me and arranged for a courier to send me a new handset but instead they sent me another faulty 2nd hand phone that looks like it had been recycled. now i want to cancel my contract and mtn is telling me that i will liable to pay an early cancellation fee since i am breaching my contract, how am i breaching their contract when they have done nothing to help me but they keep on sending faulty handsets</p>