Coin-doubler? What it is? Real ornot?

Hello fellas, i heard and have seen @coin-doubler account and it says that the coins or steem tokens will get doubled in 57 or 58 days.

For example if we transfer 5000 steem to @coin-doubler it will give back 10000 steem in 57 or 58 days.

Its good if our coins become double and i have seen some of the users that it mentioned who used coin-doubler to make coins double.

But the thing is all user's posts are only about @coin-doubler and how they got coins double and nothing about any other.

I don't know who is operating @coin-doubler and yesterday i sent 1 steem to @coin-doubler and they sent 0.001 steem with a message

I don't know to trust this @coin-doubler or not because they won't write and post anything and there is no communication option to contact with them.then how should i have to believe @coin-doubler.suppose if i send all my steem to them and what if i don't get my steem back? How can i contact them.there are some loop holes to believe this @coin-doubler account.hope they will respond and give their response about it.

because we can see @tipu and @upvu write about their project and post it and will respond to comments.but i cannot see any thing like that in @coin-doubler.

Thanks
@summisimeon