How can we keep group voicemail message when call forwarding?

Hi, we have a set of users managing a Tech Support number while the usual reps are 'off'. We have rules set up for different members of the team to receive the calls at different periods through the day but if they cannot answer it goes to the personal voicemail of that person rather than the tech support one. Is there a way to ensure that anyone ringing in to the tech support number is always getting the tech support voicemail?