Hello and thank you for the opportunity to assist you. My name is ***** ***** I will do my very best to answer your legal questions.
Ordinarily, the fact that the landlord opted to sell his house would not allow a tenant to terminate the lease. Moreover, written notification from the landlord would not ordinarily be required. Accordingly, based upon what you wrote, it would indeed seem that you would owe rent for March.
Bear in mind, of course, that I haven't seen your lease, and your lease may state that you have the right to terminate your lease if your landlord opts to sell the house, or fails to provide notice of such decision. If so, that would change my answer. That said, I have never seen a lease with either of those requirements.
I am truly sorry that my answer may be bad news for you, but please understand that it would be unfair to you (and unprofessional of me) to provide you with anything less than an honest response. However, if your concerns were not satisfactorily addressed, then please let me know, and I will be happy to clarify my answer.