non-VoLTE 3G phone

I happened to see online that as of January 3, non-VoLTE 3G phones would not be supported. I purchased my LG phone at an Xfinity store in 2017. I called LG and was told that LG-M322 will not work with 5G. I was not notified by Comcast that I need to purchase a new cell phone for my mobile account. Please advise me. Do I need a new cell phone? Will I get a refund for the one I purchased at the Xfinity store?