What could be the cause of this?? Can you tell us? Yes you can try posting on their social media accounts. Post there, they always care for their market appearance than anything else, well most of them.
It all started when Someone hacked my account (probably thanks to keylogger).
First withdrawl went quickly out (0.09btc).
Second ( my whole balance) withdrawl 0.36 btc got stucked. (After i hit " freeze my account" link in email.)
I reinstalled my PC system + added 2fa everywhere + new passwords.
After that, i raised a ticket on their support centre.
IT is 27 days today without a single reply from poloniex support.
I will try their social media accounts. ( but have only fb...)