If you are the buyer and have paid for an item which has got lost in transit do not waste time contacting the seller who may - as here -argue.
EBay's system is simple. Go to the purchase in your eBay. Click on the drop down and use "I did not receive this". If you are within 30 days you will get a refund unless seller can show delivery by tracking.
If the seller does not refund then after 4 days escalate the case to eBay. Above all do not be taken in by anything from seller. If he says - for example - "I cannot refund unless you close the case" do not do so. If you do you will certainly get nothing. @jacar_8491