Unfair declined claim

Lost my phone on contract. Been paying mtn insurance and i was contacted to be told my policy will be cancelled by the end of December 2018 and i made a claim for lost phone before the date specified .they told me my policy was cancelled with immediate effect yet I received no communication of such and i was still paying the insurance bill and I called MTN Customer careline just to be told that the insurance is still covering me. They kept on billing me and i received no communication of cancellation with immediate effect. They are just refusing to help out with my lost Huawei p20 lite