It could be it hasn't been correctly dealt with by the seller. VAT would be charged at 20% to bring the item in to the country hence the £36.00 However the Parcel force item could include duty and their £8 border forces fee. So What does it say on the label from Parcel Force?
IF you believe you have paid vat twice no need to talk to an ebay bot, this link should help you:
https://www.ebay.co.uk/help/buying/paying-items/paying-tax-ebay-purchases?id=4771
Read the article and towards the bottom there is a heading titled "Request a VAT refund" with a link to complete the form and upload proof that its been paid twice.