I just opened a case with ebay as the seller didn't ship my item. Will that effect anything. I will they not give me my refund back.
The refund goes to your Paypal account.
If you backed your PP account with a credit card (which is actually a good idea) the refund goes directly to the card.
however the money and the bank account associated is mine
Most eBay IDs are 'fake'. Very few use any version of their own name.
And your PP ID is an email.
If your Seller offers a replacement, refuse. It won't arrive either.