Partial Payment After 3d Notice

[Kevin Breslin]

I gave instructions to pay at my mailbox instead of to bank account in seperate letter with the 3d late notice. Tenant payed about %15 of what is due into bank account anyhow. Tennant acknowledged 3d notice but said no insturctions were included( the instructions were definately attached). I Closed the account this morning. 

Do I have to returrn the money to keep the 3d notice valid? Even if I re-issue the 3d notice how do I keep the tenant from keep paying dribs and drabs and pushing 3 day window.