Isn't the extra "have" unnecessary as "could've" already means "could have"? I think the correct way to say this is either "you could have had this" or "you could've had this".
"You could've have had this" is incorrect grammar. The extra "have" is not only unnecessary, it is forbidden. It is a plausible mistake for someone to make, especially in writing (doubled words are a common writing mistake). But it is absolutely no more than a mistake. The fix is, as you suggest, to remove either "have" or "'ve".