I'm not trying to down you or anything, but you say you have a WEMC already with the Dividend. So why is upgrading your Diamond to a mere WMC so important? With WMC/Signature/etc, if you have one, you basically have the benefits, and that's that. I spent a lot of effort getting my Quicksilver upgraded to a Signature and at the end of the day it was a waste of time considering I don't really use the benefits and a few months later got a Cash+ Visa Signature anyway.
I realize using the benefits is an individual thing, but my point is that since you already have a WEMC, I would not worry too much over upgrading the Diamond. You can certainly speak to the social media team or EO again and see what you need to do, but it may just be that accounts have to be "eligible" in the computer and if yours isn't, it isn't. But I wouldn't lose sleep over it either way. Good luck.
