iTunes Library on Windows 8.1 is corrupted

Computer running Win 8.1 was corrupted during update and operating sys and iTunes had to be reinstalled by BestBuy Geeks. They backed up hard drive 1st but when I got computer back songs in albums were duplicated random numbers of times. Sometimes 3,4,6,11 times for each song. Took it back and they ran some kind of duplicate removal software. Now some albums are OK but some only have 1 or 2 songs in the album. My only uncorrupted copy of about 250 albums in on my iPod. Can I restore my music from iPod to my computer? If so how?