No service keeps showing

Hi, recently, an update occurred on my phone and ever since no service has been showing on my iPhone. My sim works perfectly fine on other iPhones, but on my iPhone keeps saying no service. I have checked with my SIM company and they stated that the problem resides with my iPhone, and not the sim. I have tried all the solutions possible, and at times it would work but then after a while it would go back to saying no service.