Voicemail redirect/forward to xfinity voicemail app

Activated a new unlocked phone on my service.  Customer Service and Advanced Services were finally (after 3 days of multiple calls) able to activate my voicemail, but only by using *86 from keypad.  They are unable to redirect voicemails to either of the installed voicemail apps on my cell (xfinity voicemail app; phone's voicemail app).  Hoping someone here can assist.  Cannot endure one more marathon phone call, restating problem AGAIN, having to convince Customer Service the matter must be handled by Advanced Services, explaining problem statement AGAIN when I'm finally transferred, and after rep cannot fix the problem...call is dropped.  Frustrated and tempted to return to high-cost Verizon.  Never had this problem with VW and at least was able to get to a customer service rep when needed.