Hello, I have a tenant that wants to terminate his lease earlier. He sent me a 31 days notice already to see if I accept his early termination lease without paying penalties and he said if we didn't accept he would still pay the rent until the lease end, and I responded to him that I would accept it only if I found the new tenants and in the mean time, he still needs to pay his rent until the lease end, plus when the new tenants move-in, I'll prorated rent for him. 

Later, he introduced me some potential tenants. After those potential tenants passed my Pre-screen*. I sent a text message to the current tenant - he preferred text (who wanted to move out) that I may found potential tenant and asked if he wanted to do a walk through at the end of last month. I asked that because I needed him to confirm he would move out before I accept the application fees from the potential tenants.

And after the potential's background check, I found they are undocumented immigrants, I cannot let them move-in. I sent a text to the current tenants said that we would cancel the meeting. Now, the current tenant said that he will not pay the rent anymore plus will not pay the penalties because when I send a text to schedule a meeting for walk through means I accept him to move out. Now, we haven't signed any official paperwork nor finished the walk-through yet,  I still keep his deposit, he move his stuffs out already, but he doesn't let me charge this month rent to this deposit. 

Have you ever had this situation before? Any ideas please? Thank you.

*At first, the mentioned potential tenants gave me all their info, SSN, etc.. That's why I thought they could passed the screening background check 95%. However, the screening company couldn't verify their idenity, their SSN is fake.