Refusing to repair my phone properly!

In the second week of July 2015, I made a call to the call centre to inform them that my device had a problem with the speaker. I was then advised to take it to the MTN store. Upon doing so, MTN told me that my insurance company had to fix it. I then sent an email and was told that the phone would be collected. <br> <br> Long story short, we are in the third week of September, and I have had to send in my phone THREE times for the SAME problem. This third time I was called and told that there is nothing wrong with my phone and they are sending it back. I was told that it might be my sim card, which is incorrect as I am currently using it on another device and it is working fine. So, am I hallucinating perhaps? I am really disappointed with this service, as I have been a loyal customer that pays premiums every month for the past 2 years.