Did my tenant give up possession?

[Austin Colby]

Hello everybody,

In April I bought a duplex, that i owner occupy, that had a long term tenant (4+ years) in it. They resigned a lease with me on a continuing month to month basis.   Tenant is on section 8 and has been wanting to move for awhile now. She is late paying every month as well as over $300 overdue on the water bill. 

Last month she let me know that she would be leaving on Oct 1st and that water would be paid in full, i agreed. Come the 1st it seems as if she was going to move out then stated that she would need to leave some stuff until the 3rd. I told her then she would need to pay rent for Oct.  Also sec 8 put money in my acct for Oct rent. She said some paperwork had been pushed back (moving from a county to a city housing voucher program) She hasn't paid any Oct rent and the water got shut off. Last I talked with them it ended with some choice words on their end and saying  they dont owe me anything.  

After not getting any responses from the 3rd to the 8th i put up a 10 day notice to pay or quit. They responded with they will be out on the 15th and nothing else. It seems like they haven't been there since oct 1st( no sounds/car/lights/ water shut off) . Today i come home from work and its their key in my mailbox.  Did they surrender possession by doing this or do they still technically rent because sec 8 put their $ in and we havnt gone to court/served them a summons yet?

I have tried to contact them multiple times with all the contact info i have with them with no response.

Thanks