Rejected claim on Unsubstantiated allegations

My son was involved in an accident in the month of May 2015, this has been our first claim with Dial direct in 5 years. An investigator from Dial direct interviewed neighbours and with false information my claim was rejected. This has caused my car to be immobile for two months and not been repaired. The source of these false allegations is kept in confidential and the investigator refuses to reveal them. Always consider the insurance company carefully before taking policies with them especially this specific one. Till date they have not compensated me in any way possible.