I send my SBD to Bittrex and set my sale price, etc. as I see should fit the market prices. I sell my SBD for BTC. Then I can transfer my BTC to a digital wallet. I use Coinbase. I've done this a few times, without issues KNOCK ON WOOD!
I like to personally look at the market prices and what SBD is buying/selling for instead of watching an estimator.
Adding: I'm sorry to hear you had this bad experience. That stinks! :'-(