This will show you the breakdown of your transactions, any fees , promotions, postage paid.
https://www.ebay.co.uk/sh/fin/transactions
If this doesn't explain the fees, contact eBay Customer Services who have full access to your account and they can explain that payout for you.
This is the easiest and quickest way to contact eBay Customer Services, for a Call Back option.
https://www.ebay.co.uk/help/eua?id=5275&mkevt=1&mkpid
Lines open 8 a.m. - 10 p.m. on weekdays
9 a.m. - 6 p.m. on weekends.
Automated agents will be available on chat outside of the above hours.
I recommend contacting CS first thing in the morning as there's more chance of Dublin answering.
@maver_90