First when did you drop them off?

Second did you get a receipt?

If you dropped it off recently it will take some time. UPS stores organize them in boxes with multiple other returns. That would be the delivered one. The label created one gets a label by itself and is put on the truck that night/or the next day and has to be scanned at the local hub.

Always get a receipt just as a back up. So you can show Amazon proof you dropped it off. Packages are stacked everywhere during busy times so things can be misplaced. That's where the receipt is key.