refund deposit delay

Been renting through this agency for almost 3 years without skipping ant rentals. Upon giving my months notice numerous plp were cc ' in my mail only to find after I had left my apartment that no one attended to this. Weeks later I keep calling the office leaving my numbers for Debbie to call me back and she's forever in a meeting or not available. At one point I'm being told that I put in short notice. This is bull and will be taking the matter further.