Replacement NFC antenna (Apple Pay not working)

My Apple Pay is not working on my iPhone 7 Plus, and after all hard resetting of the device and all the cancelling and adding of my cards on Apple Pay, this issue seems to remain present. Hence I am wondering if the it is the NFC antenna or IC controller in my phone which has failed. If so be either one is the problem, can it be repaired and would someone have a link to purchase the parts needed to repair the issue as I am unable to find any replacement NFC parts for this iPhone model online.