Landlord keeping 1/2 of sec. deposit due to 2 week notice- NO lease
I was renting an apt. for 750 / month (paid on the 15th of each month). It is a shared situation where my roommate and I each paid the landlord separately. I gave both my landlord and my roommate 2 weeks notice before I moved out. My roommate failed to replace me in 2 weeks and now needs until the 1st to get someone in. Now my landlord wants to take it out of my security deposit for the 2 weeks of vacancy. We never signed a lease and there was not even a verbal agreement on the amount of notice needed prior to moving out. I figured 2 weeks would suffice. What should I do in this case? Does he legally have the right to withhold 1/2 of my security deposit for this reason?