eBay Problem with Seller?

[Mike]

Hey,

I purchased an item off a seller on eBay a few months ago for £310.

The item itself cost £300 and the postage cost £10.

The item arrived extremely late and I was promised a refund of £10 from the seller for the delays.

I still haven't received any type of refund or compensation and the seller has now deactivated their account.

How would I go about getting my £10 refund if possible?

I've messaged eBay support before about another issue, but never got a reply.

Suggestions please?
I had also previously opened a dispute on this seller because the item had not arrived - therefore, I was unable to open another one about this problem.