I once had a lot of problems with poloniex. But I have left the market a few months ago.

In December 2017 I experience pending withdrawal with SC (siacoin) after submitting ticket In 47 Days the case is complete. But after this, my verified account level 2 arrives "It was downgraded to unverified, and I spent about 30 days to get it done." I guess the customer support from poloniex is less responsive in handling the problems on the users.