You can try requesting a download of the 2015 desktop installation file to be pushed to your download account from TurboTax support.
If support will not provide a free download then you will need to go to this website to purchase and download one of the 2015 desktop editions - https://turbotax.intuit.com/personal-taxes/past-years-products/2015/
See this TurboTax support FAQ on how to contact Support - https://ttlc.intuit.com/questions/3401489
Submit your question/problem during business hours and then use the option for Call (a phone number will be provided for Call) to speak directly with a TurboTax agent -
Note: The Call option will not be available when TurboTax Support is closed.
Support can also be reached by messaging them on these pages https://www.facebook.com/turbotax/ and https://twitter.com/TeamTurboTax
