Are e bay allowed to take money to refund a customer without my permission?

I sold an item on e bay and the customer claimed he had not received the item. After emailing customer asking whether the parcel may have been taken as he lived in a flat or to check with post office regarding the parcel delivery - I sent a copy of proof of postage. The customer put a dispute into the ebay resolution centre. I have now found e bay have taken the money from my pay pal account without asking or even informing me to refund the customer - do i have no rights at all as a seller trying to make some money for extras for the family.