Product: Checking or savings account

I opened a promotional account with Citibank on XX/XX/2021, the promotion that was offered to me was to deposit {$50000.00} for 90 days and I was supposed to receive {$700.00} cash back, when I tried to fund the account the banks system was unable to verify my other bank information and didnt allow me to fund the account, I tried multiple times and I wasnt successful, the account closed since it wasnt funded, I then talked to a supervisor of Citibank and he told me to open a new account and fund it with {$50000.00} deposit and that he will make sure to make notes that the previous account was closed due to a system issue. I opened the account in XX/XX/2021 and funded with the {$50000.00}, they also requested to open a savings account which I did, the savings account remained XXXX balance since they said that only one account needed to have a balance {$50000.00}. The terms of the promotion mentioned that you need to keep the funds and both accounts open for 90 days, I kept the funds for 90 days and called to ask for the cash back, they told me that I needed to wait another 90 days to receive my funds, I talked to another supervisor and he reviewed the terms of the promotion and he said all the terms were met because even though the savings account closed due to XXXX balance, it closed after the 90 day requirements. I waited another 90 days and didnt receive the cash back promotion, I called multiple times and in total I talked to 4 supervisors and they all assured me that the promotional terms were met and that I just needed to wait for back office investigation. The back office first send me a letter explaining that the promotional terms were not met because the savings account was closed in XX/XX/2021, the account was actually opened in XX/XX/2021 and closed in XXXX so back office information was incorrect, so I called again and talked to another supervisor, she reviewed the case and said that the terms were met and that was just a mistake and that she would open another case and have it solved, then a receive another letter from back office saying that the promotion terms were no met because I had a prior account with the bank, I explained to them multiple times that the prior account was opened but I wasnt able to fund it because an issue with their system and that one of their supervisors make notes on it about the issue and assured me that the account will qualify for the promotion, they still refused to honor the cash back promotion, the last supervisor I spoke with was XXXX she was extremely rude and while she acknowledged that she can see all the notes that the prior supervisors added, she told me she was not able to help me, she kept me waiting on the phone for 35 minutes yet didnt resolve the issue because she wasnt willing to do it. The bank is deceiving their customers offering cash back but they are not honoring the promotion and they are just making excuses to justify their practices. I have kept the money in their bank for 7 months and have lost a lot of months of interest that I could it earn in a different bank, after the 90 days of the promotion passed they assured me the terms were met and to keep my funds in the accounts for another 90 days but now they are saying terms are not met, if that is the case why they were dishonest and made me wait an additional 4 months with the promise that they will provide me with the cash back.