All account tiers are now subjected to bittrex recent account disabling/freezing cases. I've seen cases where their enhanced account reverted to unverified which is why bittrex freeze their accounts and are asked to submit documents again. I'm not sure if op's case is also like this since the information he gave isn't enough.
do someone has slack invite to bittrex?
they locked up my withdraws
will pay 200$ for slack invite to bittrex channel
As jhenfelipe said, Even if you're enhanced, it doesn't guarantee your membership there. This confirms it:
As of this writing, the Bittrex team is still working on a mechanism for our enhance verified users to be invited to the Bittrex Slack channel. Please check back later for further instructions.
But you can still try to get an invite from bittrex (If you're enhanced) and after that log in here:
https://bittrex.slack.com.
I think only bittrex can give you an invite there and don't even try borrowing from someone that has an invite, No sane person will do that.
Just an add-on, I've heard if you're rude or don't follow their rules there, they will ban you.