Don't call YYZ - they don't answer - and the answering machine is almost always full. My dad was able to leave a message once, I think, but it was days before he heard back.

I always call other stations if I needed to talk to the office, about CANPASS previously, or NEXUS now. All the offices should have all the info (unless you are trying to book an appointment). YVR is the best for this, IMO. They almost always pick up the phone, and they were the ones who were trialing NEXUS back in about '03 or '04, so most of them really know the system. Plus, most importantly, they are open 7 days a week.