Find the item in orders and then look at 'order details' to see a breakdown of payments and charges.
It looks as if postage was set at £2.94 for Evri tracked. Did you then buy another postage label through Ebay?
I know Evri charge a surcharge to send from England to NI - has that led to this cost?
"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)