If you haven’t heard from the buyer in about 3 days, I would say go ahead and report him as a non-paying buyer. Reporting someone as a non-paying buyer will do 3 things:

1. It will delete the buyers account for not paying
2. It will automatically renew your listing for sale
3. It will automatically refund your selling fee invoice

To report a nonpaying buyer:

• Login to your GA account
• On the left hover over “Selling:Ads”
• Click on “Non-Paying Buyer”
• There you will see the Buyer, the transaction, and on the right there is a link for “Nonpayer Strike”
• Click on “Nonpayer Strike” and complete the steps.

Like I said, people generally allow 3 days to hear from a buyer/seller before they move on.