What confuses me, is that you get a statement which is payable every month. Setting aside the cancellation; you would still be making your monthly payment for the balance due.

So, what would there be to be "passed" to a UK Law Firm.

I way I see it :

I owe AMEX €32.000 on my June Statement closing on the 2nd of July. I pay AMEX the €32.000 I owe them prior to statement closing. Statement closes, and generates a balance due for my next statement. In the midst of this, AMEX cancels my account. If I just pay the amounts due for the statements before the next statement period... how can there be any issue to pass on for collections?

Surely, in the UK you have proof of the electronic payments. And if a law firm is "hounding" you for money you can easily show you owe zero balance. There must be some form of consumer protections in the UK where as a law firm cannot try to collect on an account that has been paid in full (turned over from AMEX-UK or otherwise).

What am I missing here?