I confess that when someone who I’m supposedly important to ignores my text, (as in, no reply for hours or until the next day or later) I assume that I’m not important enough to them to be bothered to reply. So, I react accordingly. I’m busy too. I know that it’s not always easy to have a conversation when you’re not up for it. But it takes seconds to send a quick message to say that you’ve got it, and you’ll respond in more detail later. If you can’t be bothered to do that, then unless you’ve got an extremely legitimate excuse (someone died, you’ve become terribly ill, you’ve been robbed, your phone has been stolen, etc.), you’ve just told me everything I need to know.