Miway After sales service support is non-existant

I filled in an online quote to sign up for vehicle insurance with Miway. I received an immediate response. However, the address that they have captured is incorrect. When I attempted to get the correct address reflecting on my policy - I received terrible service. I was promised a call back and my call has still not been returned. I need this urgently for vehicle finance!! I am considering cancelling this policy since after sales service is so terrible!!