For the record, my Concierge is also a "Cathy" (real name) and she has been outstanding.
When I reach out to her, I do so with a single, clearly-defined request, so as to avoid any confusion and need for back-and-forth clarification. I also only ever contact her via email (she told me in her introductory message that email is the best method to reach her).
She (or another Concierge) has always responded within a day, and has successfully handled whatever I've requested. Once or twice she has even worked directly with a property to arrange something above and beyond the WOH rules and regs.
Also, I always follow up with a thank-you email. Like in any other professional relationship, it can only help.
YMMV but I consider the above to be a best practice for engaging my Concierge in a productive manner.