Mac,
1. For the CO that said they would GW but it's still showing, call back. Very very often, CAs will say "we're so sorry it's still showing, we'll fix it" and what they think you mean is that it's showing as UNPAID, not that it's still listed at all. They don't generally "get" what you mean when you say a collection is still showing. Call back and be very specific that you want the collection completely deleted from your credit report, not just updated to paid, just to make sure they are on the same page as you.
2. For the student loans, I've learned they are pretty unwilling to budge. I GW'd that I was overseas for my DH's deployment & got the standard "we can't change accurate info." It wasn't until I found the wording for the HEROES Act of 2003 that stated they legally couldn't (by decree of our lovely president) list my account as late during the period of his deployment that they agreed to remove it. Really, they should have told ME that the HEROES Act would protect me, but they either didn't know or didn't care. So, if you, your spouse, or your parents have been activated or deployed recently, you might have luck but other than that, maybe not so much.