Malicedsoul

I was EV training my Eevee and it started to evolve into an Umbreon, I declined it initially but it was like 4-5am and I had a lapse of concentration and ended up accidentally clicking yes part way through the EV training. I understand that it's not likely that I will be able to get it reverted but if there is any chance whatsoever could someone please help me get it back to it's Eevee state? It was perfect for a Flareon, amazing IVs, I'm beyond gutted. I've only recently started playing this and it was such a strike of luck to have acquired an Eevee with such high IVs and now I'm totally deflated. If maybe it's impossible to revert an evolution, would it be possible to roll my account back to before it was evolved?