Well to round off this sorry tale of Citibank's incompetence, I've now finally received my replacement card... almost 2 months later!
I initially asked for them to send the replacement card to my address in Austria. Turns out they misspelt my address (despite me literally spelling it out for them phonetically over the phone) and the card never showed up. So about 3 weeks later, I corrected the address and they tried sending a new card to Austria again. Another 3 weeks later, it still hadn't arrived so I called and they informed me the letter had been returned to them a week earlier (nobody bothered to contact me when this happened). So, for the third attempt, I asked them to send a new replacement card to my Australian address instead and they agreed.
Well, today the third card that they tried sending out - the one that they promised to send to my Australian address - showed up in my mailbox in Austria. The address is still misspelt, the postcode is wrong and the country is written as "AT", so I'm amazed it even arrived, but there you go.
I cannot believe the sheer incompetence here. How can a bank continuously send credit cards to the wrong address?
Edit: I just tried to submit a formal complaint about this on their website, and got an error message.