Not sure who this someone was who had access to your account, you do have a Best Offer on that listing, did you set it to allow a certain offer if made to be automatically accepted? That's the only way this could have happened here.
You cancelled the item, but the fee must have been a listing fee, these are all non refundable fees, payable sale or no sale.
It's quite a high fee was it a Reserve? Then, it's payable, not liable for a refund. Don't use reserves they are expensive, just list your item for the lowest amount you are happy to receive, it cannot sell for less.
This will show you a breakdown of your transactions and any fees / postage paid.
https://www.ebay.co.uk/sh/fin/transactions
@ewelingreza0
