|I read their support agreement for paying customers, and it states they are not obligated to give you support for non-core Google services. This means you trying to get support for anything other than Gmail, Calendar, Groups, Talk, Docs/Drive, Sites, Video, and Contacts you may be SOL.|
One thing I remembered were users recommending the author of this submission to get Google Apps for support.
However, Google Voice is explicitly one of the services they list in their "additional services" that is not included in the support agreement.
I was planning to pay for Google Apps just for the support, but it just seems like a crazy idea.