Their
representative here hasn't been active since November 2018. Their social media hasn't been active since January either.
I managed to find this article which was posted on the 29th of April:
https://btcc.kf5.com/hc/kb/article/1274417/This:
The minimum amount required for assets transferring after 15th of May 2019
Shows that it would still be possible to access and withdraw your funds after the 15th of May as long as you meet the mentioned requirements.
The way they are handling this is very unprofessional but I'm not aware of anything from the past that shows that they are a scam so my suggestion would be to simply contact support and wait for their response, also check the website from time to time, it's possible that they are having maintenance.