Leave but not your money

I joined discovery insure, took cover for my car and home contents according to my set budget and later on they phoned me and told me that my cover has no surge cover and they want to add it for me, which I believe the deliberately left out so I can sign in. So when I rejected the cover because it affected my premiums I asked for a cancellation but they still debited and I reversed it then they sent me a letter saying policy cancelled due to non payment of premiums which affects my profile negatively