I think she should have given him a reason after they were together for a whole year, as a matter of courtesy. If she couldn't even be bothered to do that, then she can't be much of a long-term partner. Having said that, I wouldn't have called her every half hour if she was not answering — that's just self-punishment. It would be better to move on and let her try and resume things if she wanted to... that is, if he still wanted to get back together after being dropped like that!