Hi Puddicat,
We had/have the same problem and the debt collection letters are still arriving for the former owners 41/2 yrs later.
What I did, was write to the main post 'sorting' office manager and explained that names to our address were as follows: 'our names' and that 'the former names' were no longer at the address. I also went and proved it.
So, that stopped the letters for quite a while... then periodically we get the former owners debt letters which I RTS.
I am going to re write another letter to the post sorting delivery depot and it'll stop them again.
I have written to the PO Box no's on the debt letters but they really are thick as poo debt collectors.....
:D L.