Insurance claim...Good luck! No response

Our flight on the 3rd of March was delayed from George to Johannesburg, due to bad weather conditions. We had just over a 4 hour delay. Fortunately, I thought, we took flight insurance for such circumstances. I've submitted a claim through Chubb, their insurance administrator. According to Chubb we require a letter from Flysafair, stating reason for the delay. I have sent numerous emails to their customer care, requesting same to no avail. Our claim has been withheld due to this. I requested Chubb to try sending them a email, to see if they would receive a reply, nothing.