So sad news. I haven't feel good after reading your experience. I used poloniex but now I don't use it because I don't like their trading interface even withdraw processing time is so long than other. However, if any support team taking a long time than expected then no one like this. I think every exchanger will need good at support facility not only Poloniex but also all.
Poloniex is a big exchange and has been with the cryptocurrency market for a long time. It was once the No. 1 market in the market but now has a lot of changes and Poloniex does not have the incentive to attract investors. . At the moment, I also rarely use Poloniex because it has very slow transaction time and high fees.