Buyers have 4 days to pay and eBay do send a reminder after 2 days, so your buyer will be receiving a message soon.
I always found with the majority of auctions there isn't an immediate payment as the bidder may well not be watching the auction end .
You will need to asit the full 4 days and then you can cancel the order citing Buyer has not Paid. This will give them an unpaid item strike, they are only allowed one, and only then is it safe to relist.
If they end up not paying, block them too from returning, and ruining any more of your sales.
https://www.ebay.co.uk/bmgt/BuyerBlock?
@pejush
