Buyer said he returned an item but it hasn't been received by me yet. He is demanding a refund.

[lakatoi4]

Buyer has over 1,000 feedback with no negatives or neutrals. He bought an item, stated it was not as described and asked for a refund. I did make a mistake so agreed to refund once he sent the item to me. He claims he has sent it back but it hasn't arrived. He is now demanding a refund. Item was below my stated level for registered post so it was sent via regular post.