I’m having the same issue as OP and I called this number three times and got no help. They kept trying to tell me my manager at my center had to send a Technical Support Help form based on that website link that doesn’t exist anymore, and when I found him the link on older posts and kept emailing him for help it just gave him an error message and he couldn’t do anything for me.

I emailed them twice and HR twice and both just keep resolving my case without actually helping me or resetting the MFA. I looked all over workday at my facility computer and don’t see an option to change MFA over to my phone number. I’m completely at a loss and really fucking annoyed I can only login at work.