Loads of BS

I have a credit due to me from an account with Dr. Rawlins. His practice closed while I was in hospital. When I went to his old secretary I was told that VeriClaim took over the account. When I eventually got hold of VeriClaim I was told that I cannot get my money because the practice is closed. Really? In their accounting they must have an entry for "money due to patients". In law this is called "unjustified enrichment". If I was the one owing them, I'd be getting calls and threatening email.