Sorry to hear this. As has been said at least everyone is OK.
You may have seen or recall my "hit and scarper" incident quite a while ago
https://www.the75andztclub.co.uk/for...d.php?t=321703.
This was resolved by me through the third party insurance without my insurance company getting involved (save being told as I was required to do) and eventually fully resolved. Yes she was written off but I had the offer of buying her back so if you want to keep her then there's a fighting chance that you'll be able to; albeit with a Cat whatever (N?) marker put against her.
You might not be able to do this if Admiral have formally dealt with your claim. What is their position - If they have made a decision on your claim I think that they have the right/power to just write her off. You might still be able to buy her back and argue about her value but you need to know their formal/contractual (their contract with you when you purchased their insurance - what clause are they using? Specifics and details are crucial. Push for "we used clause 1-27-a-ii" not just "we can and have written her off."
My suggestion/recommendation is to (a) contact Admiral to find out their position and IF you might be able to bypass them, (b) contact Hastings yourself and find out exactly who is doing what and who (yes, their name and position in the company) authorised it.
Remember to keep very good records. Email and online chats with screenshots are great because they are absolutes, not a "remembered" phone call (although these are usually recorded).
Good luck.
Andy.