Third party claim unfairly treated

On 21 November 2018, I was involved in an accident in Woodmead with some lady, she claims that I’m the one who was wrong when she was the one who drove into me. She was avoiding my calls as I wanted the claim number from her I sure who happens to be Bryte Insurance. I then submitted a third party claim with all the required information and documents, they then came back to me saying I need an independent witness because both parties have given them different descriptions of the accident and that they are refuting my third party claim which I feel that it is unfair to me because the car that caused the accident is fixed. My witness was my passenger at the time and they do not want her details.