Can my old apartment complex legally keep my deposit and refuse to tell me why 30 days after I vacated?

Under the law of all states in this country, once a tenant vacates, the landlord is required to return the full security deposit placed by the former tenant within a certain time frame (21 to 45 days) and if not, within this time frame return all unused security deposit with receipts and an itemization for what the security deposit was used for.

In the situation that you are writing about, I would write your former landlord and request the return of your security deposit in full by a set date and if not, receipts and an itemization for what the deposit was used for need to be provided. Keep a copy of it for future use and need.