Refund fraud
Tricking a shop into refunding a purchase the customer actually received and kept.
What separates it from friendly fraud is the route. There, the customer goes to their bank and files a chargeback; here, they go straight to the merchant's own support desk. The classics are the parcel that "never arrived", the box that "was empty" and the return containing something other than what was bought. Buying clothes, wearing them for one evening and sending them back is called wardrobing, and sits somewhere between fraud and bad manners.
In the 2020s it turned into a service. Groups on Telegram and forums offer "refund-as-a-service": the customer places the order, the group handles the support contact with rehearsed scripts and takes a cut of whatever is refunded. It is social engineering aimed at agents whose instructions tell them to be generous. Retailers respond by weighing parcels and scoring customers who return unusually often.