claims declining my claim to get a fone back

I have 3 accounts with Vodacom and have insurance for the phones and one of the Phones got ****** on the 6th May and we reported it and sent it the claims form. when they got back to us they said that it was declined because we had other sim card in the phone. When I got insurance for the Phones I did it thru Vodacom,the insurance people didn't call to say what the do's and don't s are of having the insurance. Can someone please get back to regarding this matter coz we need the phone.