Unfortunately I can't really help you as I don't personally use KuCoin, but try using Binance[1] or Bittrex[2] and save yourself the potential headaches with KuCoin.
Though it's very unlikely that you lost your ETH, unless KuCoin is in to some shady stuff. I suggest publicizing your problem via posting on Reddit if their support doesn't reply after a few days. Sometimes this does the trick.
[1]
https://binance.com/[2]
https://bittrex.com/