It is a bit confusing are you the buyer or seller?.
As a seller you should be ok if you have the tracking saying Delivered to the collection point.
A buyer has 7 days to collect and then the item can be either returned to the seller of disposed off.
If the buyer does not get the collection code within a day of so of the item being delivered to the collection point they should have contacted ebay and asked them for it. Sounds as if the attempted collection from the collection point was too late.
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We are just ordinary members trying to help.