My funds are blocked in Blockchain.com custodial wallet (Trading account). I've been using their service for 10+ years with a fully verified account.
Once I decided to withdraw my funds, they put the transaction "In review" and it is in this state for months. Of course, I raised this with support, but I am getting non-sense replies without clear explanation what is the actual problem.
Disappointed but not surprised. They're kinda known for testing your patience when things go south and you'd need their hand to fix it.
Most recent case I remember:
Good news: after 2 months and 8 days of waiting, Blockchain Exchange finally sent me the funds. I will never use Blockchain again, let that be sure!
This was their comment:
Due to a breach of our terms and conditions, your account has been suspended. The funds have been refunded to the crypto address you have provided and the account holds no custodial funds.
Unfortunately, we are not able to provide any details about individual applications or specific reasons for rejection. We apologize for any inconvenience this may cause.
Back to your question, I know kroll.com from the crypto news I've read and from what I'm seeing they're on lots of locations including UK and Luxembourg. But I would guess, they're more expensive than the rest in the market. Have you tried writing to UK subreddits as well? for instance:
https://www.reddit.com/r/BitcoinUK/