If it is the blue starry advent calendar box you sold yesterday, you listed that one with free postage meaning you, the seller, have to pay.
Check the sold item here - it states 'free postage'.
https://www.ebay.co.uk/sch/i.html?_ssn=cassieharte&LH_Sold=1&LH_Complete=1
"There are two ways to be fooled. One is to believe what isn't true; the other is to refuse to believe what is true.”
Søren Kierkegaard, Danish philosopher (1813 - 1855)
