How can I return a called back function?

I using Angular's $http to get questions, which expects a promise in retu, either success or error:

Question.getQuestions().success(function (res) {
    ...
}).error(function (err) {});

In my method, I need to check if token is expired, if so, refresh, then make the request to /questions and retu the promise. Otherwise, just make the request to /questions as usual:

getQuestions: function() {

    var get = function() {
        retu $http({
            method: 'GET',
            url: url + ver + '/questions',
            ...
        });
    };

    if (Auth.tokenIsExpired()) {
        retu Auth.refreshToken(get);
    } else {
        retu get();
    }
},

The refresh is another $http which relies on a promise, then calls the get() callback.

Auth {...

    refreshToken: function(callback) {
        ...
        _this.getAuth(OAuth).success(function (access_obj) {
            //set token
            callback();
        })...

All of these methods are called as expected, but am getting error:

Caot read property 'success' of undefined

This is because Auth.refreshToken(get) is not retuing the /questions $http call as it should. How can I retu the promise from that back to the original Question.getQuestions()?