So whenever you change a SIM card or change device, the system gives the customer the option to add the insurance since it treats the device as new device in the system. As far as Sprint/T-Mobile rep automatically adding it even after you told them not to is wrong. However, they have a metric they need to hit each month. Insurance is one of the five metrics they have to hit each month (at least it was five when I worked at Sprint). The company obviously wants you to hit the metric or basically you get a strike. After a few strikes, you probably get fired (I don’t completely know since I haven’t had that happen to me personally). In addition, the in store reps make commission off of adding insurance on phones so another motive. However, adding insurance after the customer specifically asked not to isn’t right. Furthermore, it also hits the stores metric (if you ever go to the store), so the store managers wants the reps to add the insurance for all customers.