I ordered by email last week and phoned to provide them with the payment information:

Phone: 800-922-5255 or 406-754-2891

They said that there is usually someone taking orders from 8:00 Am to 4:30 Pm Mountain Time Monday-Thursday (and they might leave a bit earlier on Fridays). If emailing the order, include the complete mailing address and a daytime phone number in the email.