Product: Checking or savings account

On Tuesday, XXXX XXXX, I deposited a personal check for {$20000.00} with a teller at CITIBANK that my mother gave me from her joint checking account that belongs to her and my step father. On Friday, XXXX XXXX, I went into my bank app on my cell phone to check to see how much of the check had cleared. I could not get into my account so I called the bank. They told me I had to call the fraud department as my account was being closed. I immediately called the fraud department number and they told me the check had been flagged as fraud. I asked why and all they would tell me was that they had to get in touch with the person who wrote the check, I said I would have to call my mother as my step father has XXXX and does not speak XXXX. They told me they would speak to my mother. They told me to have them call the fraud department so I did that. When my mother called they told her they could not speak to her and for them to go to the bank and have the bank call them. On XXXX or XXXX, XX/XX/XXXX XXXX XXXX, XXXX, they did that. They went to XXXX XXXX XXXX whereas a person from the bank called the fraud department and thought she had straightened everything out. She told them the check was good and even where the money had originally come from. I didn't hear anything back from CITIBANK so I thought everything was done but decided to call just to make sure. They told me no one had called them from the bank and they still had to speak to my step father. My sister got his cell phone, charged it, and gave me the number for them to call him. I called the fraud department and they told me that they don't do that. They can't just call any number. This has been the situation since day one. One person tells me one thing, another person tells me something else and I cant just speak or work with one person. I have personally gone to CITIBANK twice, they don't help. I have personally gone to XXXX XXXX XXXX twice. They have tried and are still trying. They finally told me they filed a Hold Harmless Claim on XX/XX/2023, almost 2 months after this whole thing started, even though I had told XXXX XXXX XXXX  that CITIBANK told me to tell them to file the claim back in XX/XX/2023, and them telling me on two separate occasions that they had filed the claim back in XXXXXXXX XXXX, but neither bank will tell me anything else. I live in a different state than my mom and have gone 2 times to XXXX XXXXXXXX XXXX to try and get this resolved but they say that CITIBANK wont work with them. When this problem started, XXXX XXXX XXXX said CITIBANK should have called them to verify the check before they put a hold on it and they never did that. They never even called me to say there was a problem. XXXX XXXX XXXX  said they have never seen a situation where one bank wont work with the other. I have called both banks over and over and the money is still being held by CITIBANK. They will not release the funds back into my mother and step father 's account and XXXX XXXXXXXX XXXX doesn't know why they wont put the money back. Citibank had since closed my account but still has the {$20000.00} on hold. I don't know what to do. Neither bank will tell me anything. All CITIBANK tells me is that XXXX XXXXXXXX XXXX hasn't filed anything. They also told me to get a claim # from XXXX XXXX XXXX for the Hold Harmless Claim but every time I call XXXX XXXX XXXX they don't have one to give me. I called them today, XXXX and still nothing. A manager at XXXX XXXXXXXX XXXX  told me to file a complaint with your company to see if anyone can help cause I don't know what else to do. Please help. My mother is elderly and this money is all she has left. Thank you for reading this and I hope you can help.