No delivery

I upgraded my contract with Mtn on the 10th of November 2015 , I got the best service from Mtn sunnypark I then took up their insurance on the 27 the of November 2015. The device( Sony xperia z5) worked so well until on the 26 December 2015 when it just went off the battery was fully charged by then I didn't know what was the problem. When I came back from my vacation I went to Mtn sunnypark to report the problem and I was told that they have been getting same complains about the device(Sony xperia z5) so it was software related. I decided not to book it in as I use that phone for work. On the 15th February 2016 my phone fell and the screen cracked and I took it to Mtn sunnypark same day, they told me to call the insurance as i they can't book it in for me as there are papers to sign, I called the number from the 15th until today the 18th of February no answer, on the 16th February I claimed online and they said they will get back to me in 24 hour but still nothing. I can't do anything since I have be on the phone for three days with people who can't even answer their phone but they dont hesitate to deduct money from my account but they don't keep their end of the deal.