The seller sounds new to eBay and its payout process.
They need to read up about Simple Delivery, send them the following link.
https://www.ebay.co.uk/sellercentre/postage/simple-delivery?mkevt=1&mkpid=2&emsid=0&mkcid=8&bu=43952...
Unless this item was under £25 in value nothing you can do to quicken their payout, if under that amount leaving feedback can release their payout sooner.
Basically tracking needs to show delivery then their payout is released 2 days after that delivery date. Being new, they may well have a longer hold of 30 days.
As said, as a buyer nothing more you can do from your end !
@majorzeiss
