Phone missing for for three months for repairs

MTN HORRIBLE SERVICE!! Iphone missing for three months !!Handed in my Iphone 6 Plus for a cracked screen repair and still no sign of my phone!!<br> <br> My iphone is insured with MTN but due to the fact that I inserted another Sim they are not willing to fix my phone. I was not aware of this issue and I was obviously not happy since a hefty amount for insurance is being paid each month, but I do accept the terms and conditions of my contract. <br> <br> BUT now I am still struggling to get back my un repaired phone and its been almost three months.<br> <br> After poor service at the Tygervally branch I tried calling the repair center directly but always on hold.<br> <br> I personally find this so frustrating and unacceptable for company such as MTN! Please advice what the next step is.