How Scopus CSAB plan to evaluate a submitted journal's citedness in Scopus?
For Scopus, like for any organization, if you can't find anything out online and aren't getting information back via email, then the next step is to call them on the phone and be persistent in finding the right person to talk to.  

Beyond that, they are a private organization owner by Elsevier (a for-profit company), and there is no mandate that requires them to have either a transparent or a sane process, and there is likely little more advice that anyone outside of the organization can give you.