Regardless of whether this should be the lead single, or the second single for that matter. It's serving the EXACT purpose of a promotion single. People will eat it up and increase their interest for the album.
I canceled the preorder but it still says i've preordered it on the ARTPOP page I bought it though
That's what happened to me too, but I just refreshed the ARTPOP page, and before it told me I already pre-ordered it, it would show the "$14.99 Pre-Order" button for a really short amount of time and I just kept refreshing until I was able to click that pre-order button.