There's No trusted exchange site? like that one?
You can try
https://shapeshift.io/ they are pretty old than changelly also I have used them more times than any other alternatives and never had any issues.
Its better to use trading platform if you are trying to exchange large amount of coins because you might loss huge on fees when exchanging coins in these platforms.
Things have changed, there are some serious complaints about shapeshift issues in its bitcointalk thread. It sounds as unreliable as changelly.