For the money, have you looked at your iTunes account's purchase history : See your purchase history in the App Store or iTunes Store - Apple Support ?
The Apple Music Student subscription is for students degree-granting institutions, not school : Get an Apple Music Student subscription - Apple Support
If you're a student at a degree-granting university or college1, you can join Apple Music for a discounted membership price2 for up to 48 months (4 years). The time does not need to be continuous.
The Apple Music Student subscription is only available in certain countries and regions. Learn more about Apple Music availability.