Third Party Claim (Sonka Transport)

My third party claim is being rejected by One Insurance due to no independent eye witness which I am not sure why this is my responsibility only and not that of the Sonka Truck Driver who drove into me whilst busy parking. They let you get quotations etc. just to reject your claim after numerous follow up's from my end to conclude the matter. If you are in an accident and they are the companies insurer forget about being assisted!