Product: Checking or savings account

I received an email from XXXX thanking me for my {$500.00} purchase of bitcoin. I rarely use XXXX so I was not aware that they do not send emails regarding purchaes. On XX/XX/XXXX, I looked up XXXX number on XXXX and was answered by someone who identified themselves as being from XXXX fraud and secrurity department. I explained my dispute they said they were happy to help. They also text me their name and employee ID number. They had me download an app on my phone that they said would help them investigate why I had bitcoin charges on my account. They claimed that after checking my account they discovered that people in XXXX states had stolen my IP addresss and were using it on the dark web to purchase and view XXXX  XXXX. They told me I had to go to XXXX  and purchase gift cards in a certain amount, then I had to give them the numbers on the back of the gift cards. I said no. They said they would refund all the money that I spent with a security card. Since they claimed to be from XXXX I thought this refund would be on my XXXX account and I could just transfer it into my bank account. After making all of the gift card purchases and using my credit card and personal line of credit for those purchases I realized that I was being scammed. i immediately hung up. I called XXXX then next day and they told me I was scammed and to take the app off of my phone. 
I called US Bank and reported it to them. I had {$11000.00} stolen. They closed out all my accounts, opened new ones and started an investigation. I was told that unless I was told that the scammers would provide a service for me I probably would not get my money XXXX told them that I was promised a service. I was going to have the use of my IP address shut down in the XXXX states that it was being illegally used and I was getting my money refunded. I spent an incredibly long time on the phone with XXXX XXXX over many days. 
I made multiple calls and got transferred multiple times before someone would finally give me a fax number. I had printed the text messages from the scammers and wanted to show US Bank that I was being promised a service and a refund of my money. I faxed the information and was given a different claim number. After another series of phone calls to them I was told on XX/XX/XXXX that there are XXXX claim numbers for my case, XXXX for the credit card and XXXX for the checking/savings account. My previous call had been incredibly frustrating because when I thought I was talking to the department investigating my checking and savings account I was getting information about my credit card. So the information was inaccurate such as we are still investigating, your case is not closed. Which I later found out was false. I wanted to dispute that and have them continue to investigate. I spoke to a man named XXXX who was very positive and give me his direct number and was told to call back after the weekend. I called him and left messages for XXXX weeks and never got a return call. On XX/XX/XXXX I spoke to an employee who my claim was still being investigated. Obviously, I was relieved. About XXXX minutes later I got a call from a different person who said your claim is denied. 
I am angry and very frustrated. I can prove that I was being offered a service and was promised a refund. I even told US Bank that I would be happy if they would just pay off the {$3000.00} that were taken out of my credit card as a cash advance and the {$1100.00} borrowed from my personal line of credit. All they would do was remove the interest and charges for a cash advance.