Payment withheld but Item is delivered and buyer confirms

[waltherwa2000]

Payment is withheld but buyer's feedback and personal message confirms delivery but no confirmation of delivery from Royal Mail. How can I get my payment  as the automated "Assistant" does not understand..
Item #306109408233

[waltherwa2000]

Buyer's feedback confirming delivery.

[waltherwa2000]

NOT confirmed by Royal Mail.