You can use this online refund request form:
https://support.turbotax.intuit.com/forms/refund-request.jsp
Or if you have trouble with that form, here's how to speak to TurboTax Support by phone:
You can use the form at the link below to schedule a call back, or it may provide a number. Hours are 5AM-5PM Pacific (8AM-8PM Eastern) Monday-Friday.
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