You have exactly 0% chance of getting help on this matter

Not being mean, thats the honest truth. They hardly (if at all...) help people who have account issues, nor when someone accidently trashes a new 5* hero as fodder, so there is absolutely no way they`ll care about your Abyss Helmet.

Accidently? 

Just remember to lock all potential gear or good gear, it is the number 1 mistake you can do about equipment. I also did the same once with gear from labyrinth, and there is no refund for these kind of mistake 

I lost R&L that way long time ago and never got a dupe since then

I contacted the customer support but they said that if the gear is used as a fodder,the cannot restore it

Since then I always lock everything that look even slightly good

Sadly I don't think there's a way to get it back if you use it as an enhance material :(

Well if it makes you feel a bit better there is a limit of how much equipment you can keep (even with storage)

There is always new limited equipment coming out with every major event

One of those days will come a time when you might have to clean one of your limited anyways lol

Atleast it was a gear piece and not a ml5 being accidentally used as fodder, yes that actually happens to some ppl. Gear can be replaced especially if you didn't roll on it. Just be mindful and start locking anything precious to you.

I talked about this way back stating that all event and pvp gear should come pre-locked as to prevent the selling or using as fodder for other equipment, but there were some anal people that gave the most asinine reason to why it shouldn't. You are definitely not the only one, but one of the few to come forward and admit it. This should also include 5 star hero's coming pre-locked. Sorry for the loss, but that helmet is as good as gone.