Poor service for 3d party claim

I am insured by Outsurance and registered a 3d party claim against Momentum not to loose my Outbonus. What a horrible experience. It took Momentum about 3 weeks to respond after a sent them all the required forms. NOTHING happens preemptively. The goal posts get shifted continuously. For instance I gave a statement of the events via email. Their client filed a different date although I have photographic proof of the actual date of occurance. After eventually completing the damage assessment (Outsurance was the next day, 20min I had the report) and asking several times for the assessment, I was informed they need my statement to be changed. I did. Again following up a week later,they need it as a letter. Now the say the Outsurance non claim letter must be change to reflect the same date. This is now approaching 3 months. Still trying. Absolute appalling service and ethics. Not wanting to help amd having to drag answers from them. Outsurance is unbeatable un their customer focus, ethics amd assistance .