So, I had a month-to-month lease in DC. I had to leave on pretty short notice for a new job several states away, so I gave my landlord six weeks notice. He told me that I would have to pay rent for the month of September, which I accepted, even though I wouldn't be living in DC for most of that

The landlord wanted to know when he could move somebody new into the room, but I figured that since I paid the entire month's rent, I would keep the room for the entire month. Although I moved my stuff out early in September, I told him that I'd stay on the books as a tenant, and if he wanted to pay me back a pro-rated rate for the new tenant to move in, that was fine. I also told him that I would probably be coming back to the city sometime in September, and was going to stay at the house because, again, I had already paid for it.

I was planning to go back to DC this weekend, but thankfully I'm still friendly with some of my old roommates. When I mentioned that I would be staying at the house, he told me that the landlord had moved a new tenant into my bedroom.

What can I do about this? I didn't mind giving the room up early had the landlord refunded the rent that I wouldn't be able to use, but he didn't pay for anything. Would this count as an illegal eviction? I still have keys and he didn't change the locks to my knowledge, but there's somebody living in my bedroom. I also don't want to cause any trouble for the new tenant because he didn't have anything to do with it, all I really want is my money back