Just recently i was just trying to train my eevee into eventually turn into an umbreon but it just randomly after finishing fighting a npc, turned into an espeon... After all my hard work finding one and training one...

So you want to know if it's possible? as long as remember it's not.

Not saying if it is possible. I'm saying that it just happen to me that it evolved without asking me if i want to evolve it or not. So it did it regardless.

that sucks, but all of the time i have played i have never had this happen :c i guess if you dont want to keep it you can sell it and buy another eevee

I doubt that anyone would buy it. And it is hard to find a good eevee like the one i have. i even fully iv trained it. If anything if i could get a rollback on my account that would be great... By the way this happened about an hour or 2 ago.