How to handle case, item not received?

So i just started learning about defect rates today. I check and I have 2. I believe it's from a buyer who left a positive review but gave me three stars on item not as described. it was one size and apparently his head was too huge...

The second one came from a case for item not received.
-tracking uploaded to paypal
-buyer opens case a few days after item not received on time.
-Buyer could have escalated it to ebay on 29th, didnt cause I called him 2 explain.
-buyer is new 0 feedback
-i respond asking him to be patient
-it doesn't come on time I call him asking him if he wants a refund or an item to replace which I will send with faster shipping
-he chooses item. I should have tracking number 2day to give to him.
-I called and asked him to close case, he said he would..still hasn't.

I can't upload the original tracking number to the case, because I ordered from another ebay member (two reasons, first class mail was taking 3-5 days longer than estimate and my stock was running low).

What can I do to get the defect remove? Call and ask him to close case and leave positive feedback?

You need to get him to message you through eBay saying that he wants to remove the negative feedback. Then call eBay's customer support and have them look through your messages. Should do the trick

Make sure you pick strong items or you'll get so many item defects. Definitely an easy to avoid-tough to solve problem