I'm based in the UK and don't ship internationally. I received a message from a buyer based in Ukraine with over 3,000 positive reviews asking to buy an already low value item for as little as possible. They gave me a UK address to post the item to and stated that 'a forwarder will send it to Ukraine'. They also said that if I had any questions they'd give me their social media, which may have been an attempt to take the convo off of eBay. I blocked the buyer and unlisted the item before they could buy it as it seemed suspicious. 12 hours later I relisted the item and the same person used an alt account that's also based in Ukraine to buy the item at full price. They've violated the eBay User Agreement Policy by using an alt account, possibly suggested to use social media instead of eBay's own messaging system and they're trying to work around being based in Ukraine. Based off of their reviews this person seems to buy from sellers multiple times, and I have several other active listing for similar items to what they bought. I do not want them to keep purchasing items on alt accounts.
What's the best way to go about this?