If you change the Extra’s value in the intent, then while creating the pending intent you should use the flag PendingIntent.FLAG_CANCEL_CURRENT.
A simple example would be
PendingIntent pi = PendingIntent.getBroadcast(context, 0,intentWithNewExtras,PendingIntent.FLAG_CANCEL_CURRENT);
This is the right way and will ensure that your new values are delivered.
Hope it helps.