Product: Credit card or prepaid card

In XX/XX/2019 we used our Citi card to purchase a shower for my father who was ill. We had to use our card because my stepmother was in the middle of a bankruptcy and asked if we not put it on their credit card or finance it because it would not allow her bankruptcy to go through. In XXXX of 2019 my father opened a XXXX XXXX to transfer that balance of {$6200.00} over. The transfer was complete to XXXX XXXX. Well unfortunately in XXXX of 2019 my father unexpectedly passed away. I called XXXX to cancel his card. They said no problem thank you for letting us know we will take care of it. Well they contacted my stepmother for payment, and she pretended she knew nothing about it. We have documentation and text messages that she is lying. Well XXXX put it in as fraud and it was charged back to my card. They did not do an investigation on the card. Well in the process Citi sent XXXX a check for the {$6200.00} and it didnt clear so they sent them another {$6200.00} and it put my card at {$12000.00}. It took us four months and a lot of phone calls to finally get that taken off and it still brought it back to {$6200.00}. We disputed this with Citi since this was a balance transfer and it was on XXXX not us. Well we tried to talk to XXXX and they told me since I was not on my fathers account, they couldnt talk to me. I contacted the executive office of XXXX and they said they would investigate after filing a complaint with the XXXX. They called back the next day and said since I was not on the account they couldnt investigate. They said they couldnt verify that my father opened that account. I said because he is dead. I said you didnt have a problem excepting the transfer, but once you found out he died then it became an issue and fraud since he was not going to pay. Had he made one payment none of this would have happened. To make a long story even longer Citi has the worst customer service on the planet. Now in dispute they said they would not charge late fees, or service charges while in dispute. That was a lie they charged every month. They then took all those charges off. Here is where it gets good. Since XXXX they have told me that my account was going to be at XXXX. I said great. They said they were going to send it back to XXXX. I was told that same story three months in a row. I talked to supervisors in every department from fraud, collections, customer service, and billing. I was told by 4 different supervisors that my account would be at XXXX. I called on XX/XX/XXXX and talked to them again asking what Is the deal? They said sir on our end you are at XXXX  and you wont see it on your end until XXXX XXXX which is the end of your billing cycle. I said awesome. Dealing with them for 10 months I didnt get my hopes up. Sure, enough on XXXX XXXX that money was still on there. I lost it, I called and said how long it this going to take? They put it on my credit report. My credit went down 150 points. I called back again they said you need to talk to billing dispute. I said I have talked to them before. I called 65 times and only got a recording where you cant leave a message. I finally one day after being on the phone with customer service for 45 minutes they got someone in billing. I told her what happened she said this is customer service and transferred me back without me saying NO. Customer Service said sir I dont know why they did that it is a billing matter. Every time I call no lie, I always get collections first since I havent paid in 4 months. They will transfer me to customer service who then will transfer me to billing, who then transfers me back to collections. It is a cluster nobody knows what they are doing. Now I get a letter from XXXX for my Dad last month saying he has a credit on the card of {$6200.00}. They said we cant talk to you because you are not on the card. I said then why do you keep sending stuff to my house? They said we have been trying to send this check to Citi, but they keep rejecting it. I call Citi and they said we have never gotten a check from them. Now I call XXXX back and they tell me dates and the person they talked to about it. I asked them whose name is on the check because maybe thats why they are denying it. They said we cant tell you that sir since your name in not on the account. Who the XXXX are you going to talk to then? How long do I have to keep calling these companies? It has been 10 months, hours, and hours of phone calls. Lies after lies about what they are going to do. I have been told 10 times I would have a supervisor contact me, and not once have I ever gotten a call from either company. Can you help me before they continue to ruin by credit? I keep telling them go listen to the phone recordings to hear what they were telling me.