Unfairly Rejected Claim

Worst experience ever, rejected my claim even though I expressed the reasons why my accident happened. Should I have arrived late at work I was going to get dismissed for late coming and fatigue had a huge impact in the accident, couldn't stop in middle of nowhere as I was rushing to work to be on time. it even went further as for them asking my bank statement for that particular weekend to see if I had not purchase alcohol and there wasn't any there were no substances or alcohol found in my system or in the vehicle. I sent the bank statements and I did mention that fatigue had a huge role in the accident I was not negligent the time the accident happened.- I thought insurances were there to assist clients instead of breaking them to the core.