[Closed] Post accident insurance claim and fighting 'betterment'.

A fortnight ago I was knocked off my bike and most of the bike was bent. The driver's insurer has offered a sum that does not cover the cost of a new for old replacement. My bike was 4 years old. A new bike of equivalent spec would be circa £1100. I had suggested a reasonable replacement at £850. They have offered £600. Do I dig my heels in and insist on like for like or do I accept their offer and get on with life?