I sent an item at the end of Feb to Spain however after a few failed delivery attempts it was return

[tonyfathom]

I sent an item at the end of Feb to Spain however after a few failed delivery attempts it was returned, but it has been lost in the return post. 

I did provide tracking info to the buyer but they opened a case (and even stated that it wasn't my fault).

I appealed the case as "sent with tracking information" but there wasn't any opportunity i could find to attach the proof and now they've closed the case even though I asked how to provide proof.

It doesn't seem like a human has looked at this from the total lack of individual response... any advice?

[john1297576]

Tracking information is of no use unless it shows delivery, otherwise it is merely Proof Of Postage. Appealing was really a waste of time, the buyer did not receive it so is entitled to a refund. If you were the buyer isn't that what you would expect to receive.

You could try a claim on Royal Mail for lost in post, unless they have proof of delivery then your claim should succeed.