Where can I report my previous landlord in austin TX.?

I moved out of my previous address sep 5th, and I had gave my notice to my former landlord in writing and verbally on August 5th, we were not on a lease, we were on a month to month lease. I gave him notice 30 days before our move out date. He was not happy, and through the whole situation he kept saying we did not gave him notice and that we owed him for the full month of September. Which is not fair we only stayed five days in september, I told him I will only pay him those five days, and for him to take it out from my security deposit. He never agreed, now he calls me leaving threats in my answer machine, and I am just tired of him haring me, I do not owe him nothing, if anything he owes me my deposit. I already spoke to someone at the austin tenants council and that's what they told me, I do not owe him nothing, he owes the rest of the security deposit after he subtracts those five days. Now I just got into an altercation with him on the phone, he was just yelling at me, telling me I better watch my back and things like that, he even use profanity words on me, this guy is crazy. What can I do, where can I report him, I mean is there anything I can do about this.