Updating mongoose model array with $push and $set not working

im working with mongoose. i am trying to update my Contact module:

var ContactSchema = mongoose.Schema({
name : String,
phone : String,
id : String,
plans : [{
    name : String
    }] });

in my code i do:

var uuid = require('node-uuid');
var url = require("url");
var mongoose = require('mongoose');
var querystring = require("querystring");
var Contact = mongoose.model('Contact', require('D:/DEVELOPMENT/ANDROID_WORKSPACE/HapiServer/models/ContactSchema'));  
function handle(req, replay) {
var b = req.payload;
var excistingPhones = [];
var length = b.invitedList.length;
b.invitedList.forEach(function(value) {
    console.log("plan: "+b.name);
    var query = { phone: value.phone };

    Contact.update(query, {
         $push : {
                plans :  {
                    name: b.name
                       } 
              }
            });
    });
}
exports.handle = handle;

i tried doing simple change to the database:

Contact.update (query,
            {
         $set: { id: '11111' }
            });

but no reaction.

any idia why my db wont change?

thank you.

UPDATE-SOLUTION FOUND:

i found the solution. the update didnt work. so i did find function and then i changed the contact instance i found inside the find function and saved.