You can now trade and trade currencies with USD or CNY such as Bitcoin (BTC), Litecoin (LTC), Ethereum (ETH), Bitcoin Cash (BCH) and Ethereum Classic (ETC), depending on the coin you have. Different currency pairs.
According to Coin market cap statistics, Huobi is currently ranked 9th in terms of total trading volume over the past 24 hours.
I'm not really aware on Huobi issues recently specially related to this one. If op is the only one who do experience such thing then most likely the problem is really from the user because its quiet odd to assume that they are the ones who do make inside job and they wont really ruin their reputation for sure. Knowing this is included on top sites which do have high volume. The word of scam here is being used inappropriately.