Where can I sell my brand new Insulin pump?

It's brand new so it does not pose any health issues, and after trying to return it, i was told "not to worry about it" and it has just sat in a box since 2007. Like I said it's still new, i never used it and after getting it realized that pumping was something I could not commit to i tried to send it back but Medtronics refused to take it back. Anyway, its worth at least $5,500 and it would be a shame to just dump it when someone out there could use it! If I can't sell it does anybody know of a organization i can donate it too? Thanks!