Hi, I'm Ashik. Welcome to JustAnswer. I'm reviewing your question now, and will post back with your reply ASAP
Open "Settings". Open "notifications + actions". Open "Phone". Uncheck "Show notification banners". Change "Notification sound" to "none". Go back to "Settings". Open "ringtones + sounds". Change your ringtone, but don't choose "Pure". Close "Settings".
Then try calling to the phone and see if it rings. If not, go back to Setting > ringtones sounds and set a custom ringtone there. Please let me know if that didn't work, so I will continue to help you
Sorry, I will not be able to connect to your phone and fix it from here. But I will call you and help you to fix it.