Oh gosh, I'm so sorry! That sounds super stressful 🙁
If you still want to call Yolanda, her number is (979) 458-0379. Hopefully she hasn't changed it since I last spoke with her (last March).
On the interview portal, they also have the number (979) 862-1169 listed where you can verbally confirm or deny your interview. Maybe they'll be more receptive to helping you out on the phone call?
Other than that, I have no idea how reliable TAMU is with rescheduling interview conflicts. If you haven't already, I'd try talking to KSU. I know you said they will only change it for an emergency, but hopefully they'll be understanding of the situation you're in!