Contacted by Post Office after receiving refund for non-delivered item

[redhappyhats]

I've just received a simple form from the Post Office enquiring about an item that I had a refund on after non-delivery.

I won the item and waited for the expected date of delivery, after two more weeks I still hadn't had anything so I started the refund process which successfully went through.

Now near 5 months since I won the item the Post Office are asking detailed questions about the item, I get the impression that the seller is still pushing that I received the item.

The item price was for £4.20, what should I do? as far as I'm concerned the item has gone through eBay resolution and I've had a refund.

Unfortunately I've noticed that on the Post Office form in small writing on the bottom it says that if I don't reply they will assume that I did receive the item.

We've always been told to send all correspondence through eBay messages so why has the seller contacted the Post Office?

I'm very reluctant to sign a confirmation form without knowing what it will be used for.

Any ideas?