Windows Itunes library file damaged

I have the latest version of Itunes on my pc. I synch a number of apple devices with it. I keep a substantial library of music and podcast on it. Through a series of mishaps the the library file has become corrupted/damaged/, I have had to rebuild the library. I have been able to start on the music library and it looks like I can fix it. The problem comes with the podcast directory. These podcast are files that I have downloaded from various sources on the net.They come in mp3 form and some subscribed podcast through apple . The current podcasts consists of a mish mash of duplicates, folders of files. misc and random files. My original podcast library was about 800 megs but the file now shows about 30 gigs of files. I have managed to remove some of these files from itunes but its still a mess. I have been on with Apple twice, once they promised to call me back but didnt and the other time I was disconnected after 2 hours of trouble shooting. Does anyone know how to make repairs or replace the library file?

Thanks