Approved claim rejected after 4 months

Logged a claim on 10 October 2017. Received notification 16 November 2017 that claim was approved and contractor allocated. Received no further feedback and after numerous emails, telephone calls and complaint logged to their complaints department, I am told that the claim was rejected. This feedback given to me only on 5 February 2018. Totally disgusted with the service received. When trying to cancel this insurance I am told to give a months notice and proof of new insurance. Never received such poor service!!!