If you've already issued a refund but the buyer hasn’t returned the item, that's frustrating. In most case, if a buyer doesn’t return the item within the specified timeframe (usually 45 days), if you used Amazon’s shipping label you're eligible to file a SAFE-T claim to recover the refund amount. It’s super critical to follow Amazon’s process and only accept returns through Amazon’s official return system. In this way, you are protected and everything is tracked. Don’t arrange returns off-platform or communicate outside of Amazon messages, otherwise it becomes really difficult to get support or file claims. As for contacting Seller Support, you’re right, they don’t give out phone numbers directly anymore. But you can go to Seller Central > Help > Get Support, and from there, you can request a callback or open a case through the system. Hope this helps!