That is not the way to do this.
You must open a NOT AS DESCRIBED CASE, seller provides return label,and on return it is best to get a refund.
You are only allowed one case per purchase and if seller does not send replacement, or item is faulty, you do not get a second chance.
Only by doing returns through the ebay system can anything be enforced. Just returning at your expense and you will be lucky if you hear from seller again.
It does not sound good if seller asks for your address, he already has it for original purchase!!!!