Finrite insurance

I have bought the cellphone last year April and asked the insurance to be added ,I only found this year that the insurance was not added and they kept saying that I had cancelled it ,upon requesting the voice record they said that they will put the phone under insurance as it was their fault for not adding it last year and will reflect as if the insurance was taken last year and then they will start deducting I am now in shock as they ask me to pay the access of R5100 saying that the insurance was still new but had they added the insurance when requested that would have not affected me I would pay the Normal access but now they want me to take their fault