Product: Checking or savings account

I opened a checking account online at CititBank ( last XXXX of account number are XXXX ) and deposited {$30000.00} on XX/XX/XXXX in order to earn a {$500.00} bonus. The flyer that was sent in the mail about the bonus stated Its simple to earn your cash bonus. Open a new Citi checking account between XX/XX/XXXX and XX/XX/XXXX. Within 20 days of opening your account, deposit the required balance in new-to-Citibank funds into the new checking account. Maintain the required minimum balance for an additional 60 consecutive calendar days. I did all of those steps and maintained the required funds until XX/XX/XXXX which was 70 days, 10 days longer than the required 60 days. I was supposed to receive the {$500.00} bonus 30 days after meeting the requirements. When I didnt receive the bonus, I called CitiBank at XXXX. I spoke with a woman but dont have her name. She initially told that me that I had met the requirements and she would check on why my bonus hadnt been deposited yet. When she came back to the phone she said the bonus would be deposited on XX/XX/XXXX. When I questioned why it would take that long she put me on hold again and when she came back the second time she told me that I hadnt actually met the requirements because I didnt hold my funds for the 60 day required period. When I told her I absolutely had, she informed me that the 60 day holding period doesnt start until the 21st day after opening the account and they call that the maintenance period. I went back to the flyer and there was no mention of the maintenance period on the front of the flyer. I read it again and again and couldnt find anything about the maintenance period or that the 60 day holding period starts on the 21st day. There were no footnotes or asterisk or anything about a maintenance period. I finally found that information on the back of the flyer in tiny print. I obviously would have held my funds there the additional few days had I been aware of the maintenance period but that requirement was so hidden most normal people would not be aware of it. Even their own employees arent aware of the maintenance period until they do a deep dive into the requirements. They could have easily mentioned the maintenance period on the front of the flyer under the 3 simple steps listed but they didnt. I think this is deceptive advertising and really almost fraudulent. Because of their deception, they enticed me into providing them with {$30000.00} of my money for over 60 days with no interest. So not only did I not receive the {$500.00} bonus but I also lost the interest on the {$30000.00} that I could have kept in my interest bearing savings account earning over 4 % interest. If there is anything that can be done to either get the {$500.00} bonus or recoup my lost interest, I would greatly appreciate your help. I would also like CitiBank to be held accountable for misleading customers about the requirements necessary to earn bonuses. ALL requirements should be listed on the front of the flyer so customers know exactly what they have to do to earn the bonuses. Burying one of the requirements on the back of the flyer in tiny print should not be acceptable. Thank you.