HELP! Urgent credit report problem!

I'd be grateful for any intelligent help anyone can offer me with a tough situation.

We have a mortgage going into final underwriting tomorrow. Now, for the 3rd time in 4 months, my undergraduate college has reported to Experian that my student loan is 180 days in arrears. (It's been in good standing for many years.) This dropped my Experian score from 768 down to 689. (With my college's flakiness, I've been reviewing my score every day during the mortgage process, so I know what the drop was, and I know that it just occurred last night.)

1) What will this do to our mortgage? Last-minute rejection? Rate hike? We have good income and are paying 20% down, for what it's worth.

2) How can I get this rectified immediately? Having dealt with this twice before in the last four months, I know that Experian isn't especially eager to fix this in a hurry, and I need relief **now**; I don't have a single day to spare. Would it be good enough to supply a letter from my undergrad college (the creditor) saying that my account is in good standing, and this is a mistake? They'd do this for me. (I went to a small college, and know the staff well even after all these years)

3) If I get approved, but for a higher rate, can I sue the company that administers the loan for the college? (It's they who keep misreporting the loan.) If our rate goes up half a point, that would cost us $200/mo. There is a clear paper trail showing that they've been doing this to us again and again; I would hope to hold them culpable for $200 x 360 (months of the 30-yr-fixed m'gage) = $72,000. If not, how else can I recover my loss? (And no, a refi isn't the answer. By the time we can refi, at the rate things are going, rates will have gone up far enough so that it makes no sense to do so.)

I'm very, very stressed and desperate. Thank you for any useful thoughts.

 

Boy--I had no idea.

Thank you so much!!

Dave