Pending PayPal credit payment can’t be cancelled?

Description

I’ve attempted to contact the seller – after waiting weeks for an order – and had no reply.

I’m loathe to order elsewhere before I’ve been able to cancel this pending payment, but the seller seems to be able to prevent me from cancelling and can just apply the payment on a whim when they’re ready?

Any ideas appreciated, I’ve searched quite widely but all of the solutions seem to reference older versions of the PayPal system and I can’t find a link to manage a pending PayPal credit payment anywhere. So frustratingly in limbo.