You might have missed the more subtle signs. Perhaps you pushed him and pushed him and never gave him a second to think about doing anything other than fleeing your pressure. You may have to ease off a little and give him a chance to make a different choice than to run away. If he is sensitive, then he will always choose to run away from your pressure. Or, if he is really dull, then you might try adding short bursts of intense pressure to kind of wake up his brain, then give him a void of no pressure to see if he turns in and looks at you. If he does, then do NOTHING for a bit and see if he wont come to you.
You can't just have the volumn on at the same level endlessly or the horse will tune you out.