The Sim card you have should be a 'triple sim' ( see a typical picture here https://www.1pmobile.com/SIM ). AFAIK the iPhone 15 uses a nano sim, you should just be able to press out the Nano sim part of your existing sim.
Superusers are not staff, but they do have a direct line of communication into the business in order to raise issues, concerns and feedback from the community.
