Product: Checking or savings account

Re : XXXX Back on XX/XX/XXXX somebody withdraw {$4000.00} from my account ending on XXXX from one of the CitiBank branches in XXXX XXXX without my authorization. I called the bank several times to report the unauthorized Teller withdrawal and to request an investigation and a refund of the {$4000.00} on my account. Also I submitted a claim to Citibank for the unauthorized transaction on my account. On XX/XX/XXXX Citibank send me a letter to notify me that they had open a dispute for the unauthorized transaction, they also send me a statement of unauthorized use request that I needed to sign. I immediately signed the letter/document and send it to them. However I never heard from Citibank again, even though I called them several times they never gave me any answer or the refund. On XX/XX/XXXX I start calling them every week to request an update on the dispute and the refund of my {$4000.00}, after several calls, they finally told me that they never got the documents that I needed to sigh, so I asked them to send me those documents again. I got the documents on XX/XX/XXXX and once again I send them and I called them to verify they have received it. After several calls and almost two months later they told me that they didnt received the documents and that to make sure they get it Ill need to go to the nearest Citibank branch and ask them to send then for me. I went to the branch in XXXX VA with address XXXX XXXX XXXX XXXX XXXX, VA XXXX. I spoke to the Branch manager and Vice president NMLS ID : XXXX XXXX XXXX. I explained the issue to him and he assured me he was going to send the information to them. A week later again I call Citibank again to verify they have gotten the documents. Every time I called they told me that they were going to send a follow up on the investigation and they will contact me or that they were going to refile the case and they were going to have an answer within 10 business days. They also told me that they were going to place a note and asked me to call back within a week. During the month of XXXX and XX/XX/XXXX I called them every week or every two weeks and follow their instructions. And once again they told me that they still havent get the letter/documents that I needed to sign and that itll be better if I fax it to them, so I did fax the documents to them. I kept calling and calling Citibank centralized dispute unit number XXXX for months and never got any letter email or phone call from them. Its been almost two years and I still havent get my refund. On Friday XX/XX/XXXX I talked to a supervisor name XXXX and she told me that the case was close back on XX/XX/XXXX. However, nobody notify me about that. For months I kept calling Citibank almost every week or sometimes twice a week and nobody could tell me that the case was closed since XX/XX/XXXX. 
Its been two years and I still havent get any answer from Citibank nor the refund for the {$4000.00} on my account. As I have stated to Citibank I did not withdraw that money from my account and I did not authorized any one to withdraw anything from my account. I live in XXXX VA and I didnt travel to NY during XX/XX/XXXX. 
Please help me investigate my case and get my money back.