My apologies... It's actually changelly.com with the double "L"
I went there just now and I must say that it seems pretty fair to me. I just tried entering a 1SBD to BTC transaction to test it out, though the minimum is about 10SBD. It charges a 0.5% fee.

It says I would get 0.00055123 BTC for 1SBD, and that translates to about $1.45 at the current BTC price. It's not bad, considering SBD is trading for $1.53 right now: http://steemdollar.com

I don't have SBD to try it out now, but I will probably do that in a day or so.

I hope this helps :)