tedster - 5:29 am on Nov 22, 2011 (gmt 0)
(i have no idea who placed them)
You've got to do some extreme due diligence to discover if anyone in the organization placed these links. One purpose would be to discover everything they did, not just the examples Google fed back to you.
Then, you undo everything you possibly can and report your actions back to Google in another Reconsideration Request - including whatever internal education and/or changes you've made. Tell them you are completely willing to have the value of any such links wiped out.
Even then, you'll probably spend a bit more time in the penalty box - how long would depend on how severe the violation looks to Google.
And if you can't find anyone who actually bought links, or entered into link schemes of some other kind (link rings or whatever), then report your efforts and that result. Disavow any connection to those backlinks, again telling Google your are 100% willing to see the effect of those links reset to zero.