I'm not sure that's true that CreateSpace recycles its ISBNs. I haven't seen a credible source discussing this, and it doesn't make sense to me. ISBNs are cheap and it would be a pretty gross misuse of the ISBN system (which are supposed to be unique even across different formats of a book).

It may be that they will "recycle" an ISBN if you start the process with them but never actually complete the publishing process.