Complaint sub-issue: Credit card company isn't resolving a dispute about a purchase on your statement

To whom it may concern : I am reaching out to you for help since CITIBANK wouldnt provide the letter that I needed in order for XXXX XXXX to pursue their investigation regarding the missing refund since XX/XX/XXXX. The dispute started in XX/XX/XXXX and XXXX XXXX finally issue the refund on XXXX and XXXX see attached since they cancelled the flight due to COVID 19 but till now CITIBANK isnt helping me track where the refund went based on the info. provided by XXXX XXXX see attached. 
XXXX XXXX provided the information that CITIBANK needed to check our refund since XX/XX/XXXX till now CITIBANK didnt do anything. They provided the info. since XXXX XXXX, XXXX and recently on XXXX XXXX, XXXX but again no respond from CITIBANK where the refund went based on the info. provided by XXXX XXXX. CITIBANK should check it with their bank based on the bank reference number that XXXX provided if not they need to respond to all the info. that I have been providing them nothing at all. 
I am the one reaching out directly to merchant regarding my refund status. CITIBANK didnt help at all. 
I have been dealing with Citibank since XX/XX/XXXX till now. I found out from XXXX XXXX that they issued the refund on XX/XX/XXXX and XX/XX/XXXX airline tickets worth {$570.00} per tickets total of {$2200.00} for 4 passengers but then when I called CITIBANK they informed me that they dont have it they only received on refund on XXXX stmt. for one passenger. We have total of 4 passengers that we are waiting for still missing according to CITIBANK therefore XXXX XXXX provided the bank reference # so that CITIBANK could verify it and we provided it via e-mail on XXXX XXXX, XXXX see attached. I also provided them the e-mail that I received from XXXX XXXX on XXXX again no respond from CITIBANK regarding the result of their investigation. Imagine dealing with CITIBANK and XXXX XXXX since XX/XX/XXXX and till now I am still dealing with them regarding my refund. Now CITIBANK isnt providing us the result of the investigation based on the bank reference and info. provided by XXXX XXXX. I was dealing with XXXX from XXXX XXXX and they want CITIBANK to provide them a letter indicating that they didnt have the refund in order for her accounting dept. to move forward with the investigation where the refund went but unfortunately CITIBANK isnt providing what I needed therefore I decided to reach out for your help. I have been transfer from one dept. to another from CITIBANK and they wasted a lot of my time since XXXX and no result at all. XXXX, CITIBANK and I did the conference call and again CITIBANK XXXX willing to help solve the issue especially XXXX XXXX provided all the info. they received from their accounting dept. 
I provided them all the documents that I received from XXXX XXXX and forwarded it to them since XX/XX/XXXX and the recent one on XXXX and latest information on XX/XX/XXXX till now no respond from them regarding the outcome see attached. 
As you can see on XXXX XXXX, XXXX letter from XXXX XXXX it was provided the same information but they didnt respond regarding the result of their investigation see attached. 
Recently, I received my recent statement from CITIBANK and my dispute amount still showing open after I provided them all the information that I gathered from XXXX XXXX see attached. 
I called CITIBANK on XXXX and they told me to give them 5-7 business days. I called today and now they are telling me another 5-7 business day. I am not going anywhere with them especially I already provided them the information that they requested over the phone. One of the representative told me over the phone to request the bank reference # which I provided to them already since XXXX XXXX, XXXX now they arent doing their part to check where the refund went. They kept telling me no refund showing on their end see attached bank reference info. from XXXX XXXX. 
I called them today XXXX hoping that they have the letter that I need regarding the investigation result based on the information provided by XXXX nothing again. 
On XXXX, I talked to XXXX one of the supervisor from CITIBANK today and she told me that she will request it today and I told her that I already request it twice till now they havent provided the letter that told me last week that they should have it today now they are going to make me wait another 5-7 business days. I asked her if they received the e-mail that I sent and she confirmed that they did therefore I asked her for the letter that I need and she told me that I need to wait again. I told her that I have been patiently waiting since XXXX XXXX regarding the letter that I requested till now nothing. In addition, she confirmed that they received my e-mail request and phone request that I sent them recently but they arent doing their part to provide me the letter about the finding of their investigation especially they claimed that they didnt have the refund but XXXX XXXX kept insisting that they sent it on XX/XX/XXXX and they provided the bank information. I have been waiting for this letter since XXXX. I asked her if they received the refund from XXXX XXXX that they released on XX/XX/XXXX and according to XXXX as of XXXX no refund from XXXX XXXX. 
I am reaching out to you since CITIBANK wouldnt provide me the help that I needed in order to check the bank reference # that XXXX XXXX provided regarding my refund that they issued on XX/XX/XXXX till now the balance of 4 airlines ticket still showing open on my credit card statements see attached. 
I disputed this back on XX/XX/XXXX. We are only three weeks away and it almost one year. I even have XXXX XXXX talked to CITIBANK bank via conference call and till now nothing. Not sure why they are prolonging it just a simple letter that I need in order for XXXX XXXX to pursue their investigation if they dont have the refund on their end then they need to provide the letter to XXXX XXXX indicating that they couldnt located the refund issued on XX/XX/XXXX and XX/XX/XXXX see attached. 
I tried to resolve it myself with them but they are just transferring me from one dept. to another no one help me with CITIBANK. Thankfully I was able to get the info. from XXXX XXXX now that I provided to CITIBANK they should provide me the outcome of their investigation if they really working on it apparently till now no outcome. 
This has been exhausting dealing with CITIBANK especially I provided them all the info. that they needed from XXXX XXXX. All I need is the letter indicating that based on the bank reference that they couldnt find the refund so that XXXX XXXX could provide the letter to their investigation team. 
Your cooperation is essential and greatly appreciated. 
Best Regards XXXX XXXX XXXX