Summer mobile is ripping people off!

My phone was handed in on 20th of December at MTN after it did not want to switch on anymore on 21 December I received an email from MTN that the phone must be replaced, since then I have been struggling with summer mobile to replace my phone every time when I phone they say they need a reference nr but when I phone MTN they say I provided summer sun with the relevant reference numbers. Then every time I phone they say they will get back to me which they never do I phone every month almost all my airtime out to find out what is going on. Today again I phone and Vincent told me he can see that they enquired yesterday again but he can't give me the feedback. When I asked to speak to the manager they told me the manager is in meeting. An hour and a half later after they promised that I will be phoned back in an half an hour I was still not phoned. When I phoned back at 12 apparently the manager is still in meetings and the person that would have phoned me back since January is still not available. This is unacceptable I am paying for a phone that I don't even have!!!!