Its been on maintenance ever since POSTOKEN got listed there. If they are using people's postoken to mint then this is very unethical move for an exchange platform.
You should collect more evidence and open a scam accusation on them and hope they will stop on their evil deeds.
To back the accusation, here is the link
https://etherscan.io/token/0xee609fe292128cad03b786dbb9bc2634ccdbe7fc?a=0x4b01721f0244e7c5b5f63c20942850e447f5a5ee. They allow deposits into their address but you will never see their address sending out. They have minted almost 14k POS. I think letting a unit of pos out of their address will reset the coinage to zero. Could this be a wrong assertion ?