My WAZE voice continues to direct me after I have arrived. How can I turn WAZE off?
Close the app
Or put it in sleep mode
Open the left menu and you’ll find a “Power” symbol at the top. This will put Waze to sleep.
However it should not continue to give instruction if you really did reach your destination. So perhaps your arrival coordinates do not match where you usually park your car or the access road you take to get there.
Maybe WAZE just wants to keep you company. 
Have you tried turning off your phone and turning it back on again? That usually does the trick for me. 
How does one turn WAZE off if the left top menu option does not show? Is “turning the phone off” the only option? Why does the top left menu option disappear too often? This was not so complicated in earlier versions!
And here we are, EIGHT years later and yep… Waze STILL likes to scream out of your pocket after you arrive at your destination. Using Waze on your phone is easy to close because you’re USING your phone for navigation. Let’s FF into 2025 and I am one of the three people who uses wireless CarPlay so the phone never leaves my pocket. CarPlay kicks on whenever I start up the car, works great… then keeps chatting AFTER arrival, doesn’t matter what the destination. That being said, I’ll take manual closure over missing the sleeping hiding PoPo-50 stalker hideout any day of the week so I’m not really complaining in the grand scheme of things. Waze well outweighs the Tourette’s outbursts of my nav app. Peace all, speed safe, and don’t ride the Titan!