Hello,
Is there anyone knows
which way to contact Hashnest.com support that is active?Is Hashnest.com be a scam?

They never replied my support tickets and hours have been passed but my first and small Bitcoin withdrawal is still 0 confirmation.
Care to share your transaction ID with us? If the withdrawal has been carried out and you can now see it reflecting on any block explorer sites, there's no point in contacting their support since it's up to the miners to process it. There's a massive backlog of bitcoin transactions due to some rogue miners ignoring low fee tx.