You would require 100 percent approval from owner fro the repayment of funds, so that won’t fly.
But solicitors threaten – that’s what they do. I would be tempted to tell them you are coming after the debt and the costs of legal action too. Hire your own solicitor and get them to issue threats on your behalf.
Thse people are stealing from their neighbours and they need to realise that’s what they are doing, not taking money from some anonymous body.