Talking to a new person on the phone for 3 days is not really a relationship yet or enough to judge anything one way or another other than to know you enjoyed talking to him on the phone. That he has not called back says he did not see a future for the relationship that you may have wanted; it takes two and he's not into it so you shrug and try again with someone else.

I would find an "easier" person to get to know, someone you meet in person and can get more of a sense of whether they are enjoying the relationship as much as you seem to, etc., maybe even quicker, so your imagination and hopes can't get as far from what really may be happening.