then method of resolved promise not called
You need to call a digest in order to resolve a promise. In Angular 2.0 this will be fixed, (and Angular 1.2 is slightly better here than Angular 1.1) but in the meanwhile you have to call
$rootScope.$digest()In order to cause the promises to resolve. This is because promises work via evalAsync. See this question to learn more about how the digest cycle interacts with $q promises lifecycle.