Reimbursed for what? I'm guessing you won and paid since you are asking for "reimbursement," since eBay charges noting to bidders to enter bids.
Did you receive the item (if not what was the estimated delivery date you were given when you paid)? Or did you receive something from the seller other than your item? There are different procedures for different problems, and "I have no info about the seller" is not especially relevant to claims under the Money Back Guarantee.
