Product: Checking or savings account

First of all, I really appreciated CFPB helps customers to have their rights and what they were originally promised. 
I submitted my 1st case XX/XX/XXXX and received the answer XX/XX/XXXX. However, I can't accept Citibank 's answer that they kept lying to customers. 

COMPLAINT ID XXXX [ Original complaint ] There is a Citibank offer last XXXX ( the offer is still on going ). If a new customer opens checking account for the 1st time, and deposits {$15000.00} for more than 3months, then I can get {$400.00} bonus. Therefore, I opened my 1st bank account and deposited {$15000.00}, and I checked with CITI banks customer service that Im eligible for the offer after I applied the promotion. I was supposed to get {$400.00} by XXXX XXXX, but I didnt get it until the mid of XXXX, so I called customer service again. The representative double confirmed Im eligible for the offer, but the back office is super busy because its end of the year. She also told me I can receive the offer in the 1st week of XXXX, but I didnt get any offer or feedback from CITI . After that, I called again, and the another representative submitted the investigation ticket because shes not sure why my case is being delayed. At that time, she also confirmed that Im eligible for the offer. She told me I could get any feedback and offer within 5 business day, but I didnt get any feedback. After that, I called the customer service more than 10 times, and EVERYTIME WAS SAME ANSWER : I am eligible for the offer and my case is under investigation with the urgent case note, and I could get any feedback and offer within 5 or 10 business days. I also talked to several supervisors, and they also confirmed it. However, I never got any feedback from CITI, and when I called last Friday, another representative told me Im not eligible because some kind of promotion code was not attached. I followed every step as the guide said, and CITI representative confirmed Im eligible for the bonus offer right after I applied, and more than 10times from different representatives every time I called. I also talked to supervisor, and she kept saying shes sorry for all the wrong information and inconvenience but theres nothing they can do. They couldnt told me what kind of code was missing because they didnt know, either. This does not make sense at all, and I can not believe how CITI bank scammed customers. 

[ My response for Citi 's response about the above case ] Citi sent me an email that I should send them the proof that the promotional offer was directed and addressed to me, but I believe that CITI bank can not send me the direct email because the offer is for the new customers who opened their 1st checking account. How can they send the direct email to a person who is not their customer? That is why CITI Bank is using so many advertisement, articles and influencers to make people to be their customer. 

I want to ask CITI that show me the promotion that requires the promo code. It was a promotion for PUBLIC not for the specific targets. Citi bank also says on their website that it's just new-to-bank, transferred from outside of Citibank. ( file attached ) https : //online.citi.com/US/ag/banking/special-offers Moreover, CITI told me that they sent me the same response for 2 times but I have never received them. They sent me so many advertisement, but not the one that I was promised to receive : their feedback. I called them more than ten times and what I heard was only 'You are eligible for the promotion. You'll get the bonus offer within 5 days. '. I just do not understand the way CITI managed their mistakes. 

Please please correct their lying and scamming customers.