I just submitted the card upgrade form to Citibank yesterday, normally how long they take to respond whether approved or reject the upgrade?

not sure i missed it or not but the website doesnt state any timeline

according the website its yes

but i dont normally it, i buy with e-ticketing.

too lazy to queue up

how does citibank contact you regards to your application status? whether reject or approve?

email/normal mail/phone ?

I read T&C only found this

Eligibility

Notwithstanding anything else stated in these terms and conditions, the following persons are NOT eligible for the Citi Prestige Feature:
a.Any Cardmember who is in default of or has cancelled his Citi Prestige Card Account, or who has committed any fraudulent or wrongful act or Transaction in relation to the use of his Citi Prestige Card.
b.Any Cardmember who has defaulted on his Card Account or Other Bank Accounts or who has committed any fraudulent or wrongful act or Transaction in relation to the use of Card Account or Other Bank Accounts with Citibank, subject to Citibank's discretion.

Probably want you to contact the agent directly