Unfair rejection of claim

I lodged a claim on the 24th May 2021 for an accident I had on the 22 May 2021. The assessment on the car was done it was declared a write off. The senior consultant was only in contact with me 7 days from the date of the claim, she requested the following documents from me, ID, Drivers license , AR, Witnesses Numbers, Details of towing company, service history and I was made to sign a consent form, which I did. It was used to obtain any other information they required. The senior consultant was very rude and disrespectful, she went from accusing me of being drunk during the accident (I don't drink alcohol), she also said I am trying to commit *****!! The reason is that a friend of mine had my car for some time when I was away and I never added him as a regular driver, well this is very funny and confusing because the time he had the car no incident was reported, besides the accident happened when me, the owner of the policy owner and the regular driver was driving. But they went ahead to reject the claim. Be careful of this people..