You cannot do anything, and neither can the seller , to speed up that payment.
Under the new Simple Delivery process, collection items when listed bought and paid for, the buyer receives a QR code, this to hand to the seller to scan , and that is the only proof the item has been collected and facilitates a faster payout.
There is no code here, the item being listed originally for posting, so the seller will have to wait 14 days for their payout.
If the item was under the value of £25, if you leave the seller feedback, that will release the payout sooner.
@colinlowen