Looking at their job board, then clicking on "more info",
sometimes at the end of Shop Comments, a scheduler's name is listed. No email address, but if you search your email high and low, you may find the scheduler's last name, and be able to discern an email address. Whether that effort is worth it, depends on the assignment and the shopper.
I agree that contact info is essential to shoppers and is lacking on their site. Since the merger of the three MSCs, specific contact info is lacking.
But, I so appreciated the last report I did for them. No frame after frame, next, next, next. Guidelines, terms, and report was all on one page. Very nice.