Not sure if you're mixing up two sayings here...i've heard of making a pig's ear as in "you're making a right pig's ear out of that" = you are doing a really bad job with what you've got. I think this comes from the old saying "You can't make a silk purse put of a sow's ear".
I've also heard "in a pig's eye" as a phrase used in defiance but have no idea where that comes from.
However I've never heard in a pigs ear