i have never used Hitbtc but i say while there is the biggest scammer called
bittrex still listed, that should be your priority. with Yobit at least you know where the problem comes from. they simply don't run wallets for 90% of the altcoins listed there. but if you withdraw the top 30-40 altcoins or bitcoin you will never have any issues and Yobit was never considered trusted to begin with.
but bittrex used to be one of the trusted exchanges and one day they decided, ummm free money lets scam thousands of users who trusted us and become rich by robbing them.
https://bitcointalk.org/index.php?action=trust;u=96390