I utilized the tried and true method of simply calling back and hoping you get a different person on the line that is more helpful. On my second call a wonderful lady was willing to work with me utilizing another e-cert and re-booking, but opening up availability on the already-booked segments that were now zeroed out. So while I blew through another e-cert, the cost was the same (change versus redeposit fee). We would not have used the second e-cert this year anyway.

It was interesting talking to her a bit about the e-certs. She claimed that US Bank wrote the T&Cs. She agreed that it was horribly worded and they run into this problem all the time, wishing they changed the wording to be more clear so as to limit angry customers (like me!).

My take is that according to their position, it is impossible to ever "change" the ticket without loosing the e-cert. As a result, changes may not simply be made for a $50 fee, but for that fee in addition to 6,000 miles per ticket. It is never one without the other. So... a better-worded T&C would say:
Otherwise it is either contradictory or redundant... poorly worded either way.

I also found it odd that I asked to just apply the second e-cert to the changed itin. She said she was only allowed to apply one e-cert to an itin. I asked why that was a problem, as they were essentially stripping me of the e-cert for changing it. She responded that it stays with the record, just doesn't give you the discount. So, the e-cert no longer applies... except that it does still apply so you can't use a second e-cert.

Bottom line is it is poorly worded. If it truly is US Bank, NW should make them re-word things. In the end NW was very helpful (the second time around) and I got everything worked out.