Reminder emails will only go out to backers that have not completed their survey in full. If a backer believes they have completed their survey but is still getting reminder emails then an error has been made.
First, search for the backer’s email in Shopify orders. If an order exists, check to see if the reward order was processed via Gift Card or another form of payment (see bottom of reference image). If the order was paid for via another payment method, we recommend cancelling and refunding the order, then asking the backer to complete the survey properly by clicking their survey link. Survey activity can only be tracked via Crowd Control using the standard survey process.