intent.putExtra() in pending intent not working

Remember to put an unique id in the PendingIntent constructor, or you could get some weird thing when you try to get the putExtra values.

    PendingIntent pendingIntent = PendingIntent.getBroadcast(
           getApplicationContext(), 
           UUID.randomUUID().hashCode(), 
           aint, 
           PendingIntent.FLAG_UPDATE_CURRENT
    );

You have to use getStringExtra() and be sure the String are not null:

     Intent intent = getIntent();    
     msg = intent.getStringExtra("msg");
     phonen = intent.getStringExtra("phone");

     if(msg!=null){
      Toast.makeText(context,msg,
        Toast.LENGTH_LONG).show();
     }

and reverse Your putExtras before PendingIntent:

   Intent aint = new Intent(getApplicationContext(), AlarmReceiver.class);
   aint.putExtra("msg", msg);
   aint.putExtra("phone", phone);
   PendingIntent pendingIntent = PendingIntent.getBroadcast(getApplicationContext(), id, aint, PendingIntent.FLAG_UPDATE_CURRENT);

Try this

Intent aint = new Intent(getApplicationContext(), AlarmReceiver.class);
aint.putExtra("msg", msg);
aint.putExtra("phone", phone);



PendingIntent pendingIntent = PendingIntent.getBroadcast(
    getApplicationContext(),
    id, 
    aint,
    // as stated in the comments, this flag is important!
    PendingIntent.FLAG_UPDATE_CURRENT);