Can terms in a lease agreement be voided based on agreements in a text message after the lease is signed?

Asked in Chandler, AZ - 10 months

3 tenants are renting a condo. Lease expires 7/31 then goes month to month. Notice to vacate is 2 months from the end of the calendar month. On 7/5 the tenants text that they will be moving out at the end of the month. I mistakenly text them back saying they need to give 30 days notice prior to moving out so they will owe August rent unless we find somebody to move in August 1st. July 27th we receieved a deposit from a prospective tentant and notified the current tenants that "Its done and they need to be out by the 1st." The people ended up backing out but the current tentants moved out by the 1st. Are the current tenants still responsible for August rent? Can they still be responsible for September rent also since that is what the lease says? Or does the text message overide the lease?