What you have written about is a civil dispute essentially a statutory violation by your former landlord to return you security deposit within 30 days of move out. It is not a civil theft in that there is no such cause of action under the laws of all states in this country.I suggest that you write your former landlord requesting the return of your security deposit by a set date. If not returned by then, your recourse is a small claims court action for violation of state statute for not returning your deposit in a timely manner.