Can't set up voicemail
I just moved my cellphone service from Verizon to Xfinity. As part of that move, I purchased an Iphone7 from Xfinity, and moved everything from my old Iphone 6. I am running iOS 13.3.1.
While all of my old voicemail messages transferred over, voicemail itself does not work. If someone calls me, they get a recorded message that "the wireless user has not set up voicemail". If I try to create an outgoing voicemail message, I get error " The operation couldn't be completed (com.apple.mobilephone error 1035)".
I am at a loss. How do I get voicemail working? I have seen that other people have issues with this, but so far haven't come across any solutions that work for me.