What state are you in OP???
Send something like this to your landlord.
Dear Mr. Lecter:?
Until recently, I rented your flat at 78 Oak Street in Monroe. Unfortunately, a job transfer made it necessary for me to move to Harding, some 100 miles away. As I explained in late May, I had no choice but to break my year’s lease on June 1, 20xx. The lease had six months left. I left owing no rent for the time that I lived there.?
I was disappointed to receive your letter dated June 18, 20xx, in which you informed me that you expect me to pay you for the remaining six months’ rent. You stated that you will keep my entire security deposit (two months’ rent) and have demanded that I pay you for the remaining four months.?
May I direct your attention to California Civil Code Section 1951.2, which requires a landlord to use reasonable efforts to rerent after a tenant has broken the lease. As you know, rentals are scarce in this town, and I would think that you could rerent my flat, which is quite nice, fairly quickly. While I am prepared to cover one month while you prepare, advertise, and show the unit, I am certainly not willing to pay further rent on an apartment that you have purposely left empty. ?
Please reimburse me for the one month’s rent that you withheld from my deposit. ?