If the helper doesn't show up, try contacting them by using the menu in your ad. Otherwise you can always abort the pick-up and select a new helper. You can only abort the pick-up once the time for the pick-up has expired.
If your ad has been marked as "Completed" without being fully done, begin by contacting the helper to see if there were any misunderstandings. If this does not solve the problem and you have more questions, please send an email to firstname.lastname@example.org and we'll try to help you as quickly as we can.
Keep in mind that no payments are made until you confirm the pick-up.