Cannot change mailbox password for My Verizon Prepaid

See problem above ... I cannot change my verizon prepaid voicemail password, when I enter my new password and do it again the second time an error message comes up saying "MTAS returned a service exception". If I try to change my voicemail password at My Verison the voice repeatedly asks me to enter a new password after I enter the number a sacond time. If I try dialing *** I am asked to enter my mailbox password, my old password doesn't work. Only after the last Verison software update did the *** voicemail ask for "mailbox" password, prior it asked for "voicemail" password. Previously my voicemail password worked and my voicemail recorded message worked normally. No my voicemail asks both callers and myself for the mailbox password.**Tried the verizon wireless support number last night again, the rep said hold on the line after I gave the problem to her, she said she would be right back, after holding on the line for ** minutes I gave up. Just now I was transferred to a rep, but got the waiting music for ** minutes, then their system hung up on me. **At least the GetHuman bot didn't send me an email again today asking if my issue was fixed. Maybe it doesn't work on weekends.**Just tried again to change voicemail p*zzw*rd, I had to change my account p*zzw*rd first, that was accepted by the system. Then it asked for my new voicemail p*zzw*rd, after entry and repeat enter of my new p*zzw*rd nummer the system said please wait, then after a couple of seconds the system says enter your new p*zzw*rd, and the loop went on for several more cycles without confirming the voicemail p*zzw*rd was changed. The other attempts to change the vm pw have all done the same with different nummers used in each attempt.

Went Verizon Store they can't help with prepay beyond selling it.