CLAIM REJECTED OVER SIM CARD.

I lost my tablet with sim card and I made aclaim with MTN insurance. Their underwriter GAURDRISK rejected my claim on the basis that I was using a wrong sim card yet I was using the insured sim card. I have been trying to get hold of the for over 1 week but I cant get through to them. MTN doesnt respond to email and their call center keeps you holding the whole day. GAURDRISK their list email adresses are not working and their numer go to voicemail or go unanswered. I ask myself if GAURDRISK is an existing company ? There is no one to clarify to as to which sim card they claim was being used with the tablet. The only reponse I got was through this platform from a guy from MTN called Mike who said his dept will get back to me but its been 1week now I cant get any answers. Iwas ****** in daylight by MTN insurance. Is there any one out there who can give me answer from both companies? Surely insuring with MTN doesnt give you a peace of mind instead it gives you HELL!!!