[Cquick]

Ok may work or not. Click or Tap whichever you prefer

click Start/ then click Phone/ then click Menu/ then click Options/ then click Services/ then scroll down to DDTM Mode and highlight/ click Get Settings/ check circle OFF that Send voice calls to voicemail during active data connection.

I had to do a soft reset and this also helped from keeping my data session from being on all the time and draining my battery.

As long as my data connection was going it would go straight to voicemail. I'm a newbie so sorry if this is not what problem you were having.