Voicemail transfer not complete

Bought an iphone from Xfinity and transferred my number from Verizon earlier this month. As I’ve seen others report here, I get no notifications when I have voicemail messages. In addition to that, the greeting on my voicemail is from my old Verizon voicemail and I am not able to set up Xfinity voicemail. I’ve talked to several people at Xfinity about this and they’ve tried everything, including replacing my phone but I can tell something wasn’t completely transferred.
I need someone to fix this with Verizon for me so I can use voicemail!