Why iPhone 7 is having no service since 2days?

I think Apple has caused its few thousand of that old and loyal customers to face the problem of having ‘no service’ on their mobile phone. I am currently using iPhone 7 with iOS 15.7. And since last four days I’m having trouble that my phone is showing no service and hence I can’t I cannot make any calls or receive any calls or messages which in fact made my life bad. It’s because you want us to buy new Apple products. For some it will be a very bad way of endings a brand’s relationship with it’s customers.