MTN Claim Denied

I insured my device with MTN which was under Pinnacle Marketing at the time and now they have changed to GuardRisk. My device was ****** a month ago and I reported it to them and gave them everything that they asked from me and filled in the claim forms. I provided them with the ITC number as well, they denied my claim stating that the insured number or Sim card was not in my insured device at the time it was ******. But I provided them with proof including that ITC number because I blacklisted everything as per requirement. I have never missed a single payment since I insured my phone with MTN. If they don't want to give me a new device they must pay me back all the money I paid for my insurance.