By this time, your return envelope should have at least started tracking back its way to your address. That being said, I have heard of CIC taking up to 3 weeks to send it back, but it would really not hurt to call them once to make sure they are in receipt of your application and ask them when will they be returning it back. A fellow worker here in my office called them up when they didn't send his passport back for about 2 weeks, and they sent it the very next day. Let me know how that turns out for you and good luck! (Wish me luck too.. April 22nd AOR and no IP/DM.. PPR is a distant dream for me still).