I have contacted them twice, via the online form, and both times received an automated response saying that their "friendly and knowledgeable" staff would contact me within one business day. It's been almost a month since the first one, and a week since the second one.

Is there a direct way to contact them? Phone?

They do respond, although sometimes not as quickly as I'd like. If I don't get a response I generally follow up - I don't think I've ever had to nudge more than one additional time. I think I just e-mail to the support address rather than going through another ticket cycle.

If you asked something that required some policy decision, perhaps that would take longer than something the first line staff could handle directly.

They have a fax number, but I don't think they publish their phone info. Ages ago I remember getting a call from them about something related to taxes, but I think it's a "don't call us, we'll call you" sort of arrangement

Since it has been so long, would suggest you take a look at your SPAM folder.  Maybe the response went there?

They do respond