If you have issues with your reward certificate, I recommend you to ask Citi Visa directly via the website. Use their Live Chat. Let us know how it went. Good luck.
I just received a Costco City Visa reward certificate amount of $358.14 in the email. I recently switched my monthly statements to paperless. This is the first time receiving an email certificate.
I guess they will send paper copies of the certificates to those who receive paper statements.
Again – You may receive your certificate on your own schedule. I receive them, usually in February.