Well, without reviewing your lease, sounds like they are trying to squeeze another month's rent out of you. Unless the lease specifies what constitutes a "writing" and how it must be delivered, I think it is a pretty weak argument that you didn't provide written notice when you did it by email and an acual signed writing. Obviously, they received the notice if they emailed you about it. While leases often provide places for procedural loopholes, this sounds like they are just trying to get another month's rent out of you. And, the argument that 1/30 doesn't provide 30 days (to March 1), I believe, is weak. Again, unless the lease is specific in it's calculation, the ambiguity works in your favor. You may find it helpful to meet with a lawyer to review the lease, and perhaps negotiate the break on your behalf. In my experience, if they are using these types of arguments to get another month's rent, you're probably going to be in a fight over your security deposit.
Answered on Jan 30th, 2015 at 9:58 AM