Cell phone insurance claim

I have bought a P smart 2021 on contract with MTN and also took their insurance to insure my phone. Last week my phone slipper and the screen broke. I tried to claim for my phone to be fixed and my claim was declined because I had a different sim card when it broke. I don't understand how does the sim have to do with the physical damage of the phone. I have never missed a single payment or paid late and I was expecting my insurance to come through for me in a time of need. I am so disappointment I don't want anything to do with the company anymore. I believe I can get a better service somewhere else!!!