Terrible Customer Service/Experience

I bought an Iphone 6+ on contract from MTN about 3 months ago in the past month the phone would fail to charge , then a few weeks ago it just short circuited blew up. when i sent it back to MTN as it is still under warranty . I was told its an electrical problem and that is not covered . That still does not make any sense to me as we are talking about an electrical gadget . They took it in , in any to confirm with supplier 3G Mobile and a month later i still have not received official feed back from either company for a phone that's costing me over 16k and i am still paying. I also had to buy a new phone as they also refused to offer a temporal phone. I know MTN are the giants of Africa and would care less of how their action actually affect us . We work hard for this money and they must be ashamed and exposed how they are robbing the ordinarily citizen, just because the own a monopoly in Swaziland . I will definitely be seek legal advise on this. This is the worst experience ever