Sorry to hear that, but this leads me to my suggestion:

Don't text or email. Call. The problem with text messages, emails, and, to a lesser extent, IM, is that they can be ignored, and the receiver can pretend to be away, not listen/notice it, or whatever. However, with a call, he needs to give you a reply immediately, and explicitly acknowledge what you've told him. It's the same for business. With elusive people, you have to be a bit more pushy and inquisitive.