It is not difficult to start a shitcoin exchange and get listed on coinmarketcap by targeting coins which aren't accepted on most of the platforms.Coinmarketcap doesn't actively track them down ,it's upto the depositor to research before blindly following them.
Everyone do mistakes, at least he tell us about the situation.
Well, rightbtc isn't a big exchange and does not provide any information regarding the company/persons who run this site.
However, it maybe a scam exchange or they have bad support.
You can read it here: https://www.google.com/amp/s/amp.reddit.com/r/RaiBlocks/comments/7o6evm/rightbtc_scam/
Some people can actually deposit/withdraw after 6 hours - 24 hours or even 36 hours.