If other people will report in the future the same story-same border-same visa type, this FB group will have an issue to discuss about. Otherwise this post would be useless...and imo it's already useless.
This story seems caused just by the "not so nice" mood of the IO today. At the end the OP sorted out her border bounce with no other major problem, as we can see from the pic of her stamp she posted above.
I just read somewhere else that the graphic and colors of the sticker for all kind of visas changed few months ago. But the point of my post is still there: the issue of a METV with 3 months validity at the same cost and requirements of a SETV.
Please pay more attention on the sticker. It's totally new for graphic and colors and there's no more the price written on it. It really looks something new. BTW: there's no sign at all of the word "USED" on the sticker either with a stamp or with a pen by hand.