Product: Checking or savings account

In XXXX of XXXX I deposited a check in the amount of {$800.00} from my frost account to my Citibank account. I have my statements from frost the check cleared to Citi and was never returned to frost. For the past XXXX  months I have been trying to simply get my money from Citibank. Citibank closed my account thinking my check from frost was fraud I called Citibanks customer service and the rep called frost to verify that my check was indeed accurate and valid. The representative then told me hes going to make notes that he verified that the check is valid and I will get a check within 30 days but he could not reopen the account which is completely fine with me, I didnt want to bank with them anymore anyway based off what they did. I called periodically to check on my check but no one can give me an answer on when I was going to get it. When I began to call everyday in XXXX, they all of a sudden told me they can not give me any information regarding my account because when I answered the question what is my mothers maiden name They would tell me Im answering incorrect. My mothers maiden name has never changed and it was always correct prior to me asking them where my check was but once I begin calling every day, asking for a supervisor and asking for answers they begin to tell me that the answer is wrong and hang up on me, which was complete nonsense because I know my mothers maiden name. XX/XX/XXXX I called again and a supervisor was able to verify me a different way ( texting me a code ) and he told me that he sees that Im owed money and hes not sure why I havent got it but he will call me back within XXXX days with an answer from the escalations team. I never got a call. So I reach out to the better business bureau. Citi assigned my case to a lady named XXXX from the executive Citibank office XXXX was useless and absolutely no help. She tells me that I have to call frost to have them pull it back from Citibank and that theres nothing she can do although I told her that I have my statement and the check cleared from frost BACK IN XXXX. And I simply asked XXXX did she even call frost to ask about the check she said thats not my job so then what is the point of investigating if youre not going to actually investigate. Citibank owes me my money. They are thieves! I called frost XX/XX/XXXX and XX/XX/XXXX and both days they verified that the funds went to Citibank and was never returned. They checked every single account that I have and it never came back. I dont understand how multiple representative can see that I was owed money and told me I would get my money via check to now XXXX is telling me I can not have my money. And her response to me on the XXXX XXXX XXXX website was that they close my account which had absolutely nothing to do with my complaint!!! She deflected and ignored the real reason why I was calling. The way they do business needs to really be investigated. If they simply called XXXX they could have verified the check cleared and give me my money but according to XXXX its not her job so I have called every number possible and have every route possible. These people all say different things, and they are all no help. This company is ridiculous. I dont want to be contacted by XXXX XXXX need someone whos actually competent and has a brain to handle my issue and to save some time because apparently XXXX couldnt find the account at first the last four digits of the account is XXXX!