Unfortunately, unnecessarily you bought the skin the second time, it was enough to wait a bit and it should be on your account if you lost the skulls. As far as I know, nothing can be done about it yet.
But I also have some good news:
As far as your bounty coins which were free currency you earned via quests - most likely you lost these clicking more than once. And when that skin you clicked multiple times on losing your coins to appears again, you most likely will receive a second version of it as well. It's more of a technical thing I don't fully understand but that's what I gathered from what I read in the dev teams chat. Best advice going forward is to click once even if you don't think it worked. That avoids you losing coins.
It seems some of these issues are from people clicking it multiple times buying multiple ones of the same.
When the skin comes again apparently it will populate again for you and there will be something you can do with it. Or at least that's what i understand from QA.