Try this online refund request form for the unconditional 60-day guarantee in desktop software:
https://support.turbotax.intuit.com/forms/refund-request.jsp
If you have trouble getting it through that form, here's how to phone Customer Support.
You can use the form at the link below to schedule a call back, or it may provide a number. Hours are 5AM-9PM Pacific (8AM-12 Midnight Eastern) 7 days/week.
Where the form asks what product you are using, be sure in the dropdown menu to indicate "CD/download" and the proper operating system, then indicate which Edition.
https://support.turbotax.intuit.com/contact
