For "several hours of maintenance." The folks at the back-of-the-card number, 855-378-6467, said "everything is down. you can't use your card and we can't look at your account." ??

Online, their website is up but shows an old balance because I made a payment that was accepted and the actual balance is $0 as registered in the payments history area.

PSA: Don't depend on Citi credit cards being reliable. Have other brands and kinds of cards because Citi doesn't grok high availability or low impact ops maintenance. I hope Costco goes back to AmEx because this is absolutely ludicrous.