Buyer failed to collect from InPost locker in time

I sold an item and the buyer generated delivery via InPost locker.  The item arrived, but was not collected in time, so has been returned to me.

I have contacted the buyer who would still like the item, but we are unable to work out how to arrange payment for redelivery. 

I cannot find any way to contact ebay and the FAQs only discuss non collection for in person collections.