Well if it were me I would not be sending anything back unless the seller pays for it first. The item is not as described it's on the seller to pay for it.

Going by these forums it's a risky business sending it back without a seller funded label.

How do you know the correct address to send it to? some sellers have a different address for returns.

How do you know the seller will just not pick up the item or refuse it? then it will be returned to the buyer.

Ring ebay and tell them seller is refusing to provide a label for the return postage.