Upgrade to Windows 10 failed, had to do complete reinstall. Now can't activate Studio 2015...

I upgraded to Windows 10, but the upgrade failed and damaged the hard drive. I wound up doing a fresh install of Windows 10 and wiping the drive. I wasn't able to deactivate my license for Studio 2015. Of course, now it tells me that the license is in use. It isn't in use, of course, since it was wiped out with everything else on the hard drive. I just need to be able to activate the software. There is no way that I have found after searching extensively to ask them to release the code. What do I do?