Who I have the same questioned this topic

I rarely use this, but I went into recently and received an error code 9999.  I closed the message box, and it kept popping up.  It said to call 800-922-0204.  But, when I checked that number, some people said it is a phishing scam.  So, I deactivated visual voice mail for now.   Oh, it was also sucking up my battery and using data that I never used.