Thank you odolvlobo for your info and reply. Yes blockchain is the hot wallet that I am currently using.So I can expect them to return the balance to my bitcoin address? Thanks again. 
The general idea is that you, as the end user, won't ever realize there's a change address. It happens, but it's not really your concern -- all you really need to know is that you spent x and have y now. So don't let the whole "change address" thing confuse you.