Tenancy at will after foreclosure?

Back in October of 2009 I received a letter from a property management company telling me that the bank they represented was foreclosing the mortgage on the building I was living in, and that I was to pay them the rent. My landlord at the time confirmed this and I paid this management company the rent for several months. Due to the foreclosure, I wanted to move into a more stable situation, but I had most of a one year lease with the old landlord at the time I was notified of the foreclosure. I did some investigation online and read that after a foreclosure a tenant with a lease becomes a tenant at will automatically. I talked to the management company and they said this was true, and so I gave them a letter terminating my tenancy. I even got it in writing (email from an employee of the company). I thought everything was fine and went and found a new apartment. Then I got a phone call from my former landlord telling me he worked things out with the bank. I told him that I was moving out and he got mad and told me that I had a lease with him and could not get out of it. Where do I stand legally in this situation? I now have a new apartment and a new lease!