As a store manager, I can tell you we sell SIMs for $20 every day. The only time it is supposed to be free is if it is defective. That being said, I usually do allow my reps to give it to customers for free if they have a replacement device through Asurion on the way as long as they get management permission first. Per audit, all SIM and handset transactions should be in our daily paperwork, and the auditor does check it. If a store has not been charging for SIMs, they will fail that section of their audit.