In this case, I would still go ahead and send them back the panel even with only half a refund, even if they do not keep their word and refuse to send you the full refund, HALF a refund is still better than a completely wasted 100 USD. Working with CN business before, I know that the level of trust between customer and business is not really that high in CN compared to Western countries. I think the reason why they want you to send it back is so they can fix it and resell it since these guys don't really want to waste anything.