Returned purchases do not qualify for Drop points. Returned items will come up on our end as "reversed" or "declined," which means our partner (at the brand from which you made the purchase) have let us know that you're ineligible for one of a few reasons, but most commonly means a return was made.
Exchanged purchases are essentially seen as a return of the initial purchase and an initiation of a new transaction. As a result, the purchase is considered ineligible by our partners because the exchange is seen as a new transaction made outside of the Drop app.
Occasionally, merchants encounter shipping issues and process a reshipment of the product. Since this is considered to be an exchange (exchange of the old product for a newly shipped item), it is treated as a return/exchange and is unfortunately ineligible to earn Drop points.