insurance was never updated

hi<br> <br> I called today to cancel insurance on my cellphone as it was no longer under contract. the cellphone was replaced with a tablet of which i am being debited monthly for however the insurance department says the insurance does not show. now if i didn't call i was not going to know this yet I've got an invoice whereby I'm being debited monthly. Now the insurance department says i must contact vodacom westgate to send through the paper work . they keep dropping the phone on me . Its been more than 4 months now and yet my details have not been updated and the policy for the tablet is not updated at the insurance department. please can someone help me.