Tenant wants security deposit to be applied to last month rent

[Shiv B.]

Hello all - My tenant's lease ends July 31 and I did not receive last month rent for July. On inquiring the tenant informed me their deposit (equal to one month rent) should be applied to last month rent. The lease specifies that deposit cannot be applied to rent and they are fully aware of this. I manage the property remotely from out of town and the tenant has now become unresponsive to messages and calls. Given the lack of time is there any merit in posting the 3 day notice to pay or quit, knowing it cannot be enforced? I also have concerns that posting this notice may result in vindictive action and additional bills for me. With no deposit to be refunded I'm quite certain I will not be provided with a forwarding address to pursue this after the fact. At this time there is no indication of a holdover but is there any preemptive action I can take to address that situation if it arises? Any advice and suggestions would be appreciated.