It's simple. The device in most cases is fine. Apple collects (through an algorithm) how often a user buys apple devices. After your time's up the device will gradually self-destruct through intricate pre-loaded bugs or updates to encourage new purchase. And guess what they all buy again anyway and they know it. The new apple products' life expectancy is about a year in most cases. Try turning off the device (or let it run out), remove it from your icloud online. Use a different wifi, icloud, sim card, and computer in a month to reboot. Otherwise free urself and buy a nokia, vertu, huwaei, samsung or any other non-slaving brands.