Product: Credit card

on XX/XX/XXXX my sister ( also a keybank customer ) and I were in XXXX. We took a XXXX minute taxi ride from the airport to the hotel. The taxi driver told us the ride would cost {$70.00} US dollars. He had to charge us in pesos but showed us a laminated conversion grid that showed the pesos we were being charged equaling {$70.00}. I have been taught to only use my credit card in high risk situations. I have been also instucted taking large sums of cash out of the US is unsafe. 
First the taxi driver scanned my keybank mastercard on a hand held machine for the {$70.00}. He told me it would not go through, that my card was declined. He then attempted to scan my credit card a second time on a device, that he had plugged into his cell phone. For the second time he said my card was again declined. I have my fraud alerts and sensitivities turned up on my cards so I did not think this was out of the ordinary because it is not unsual that I get alerts regarding any suspicious activity so I figured my bank was putting a stop to this unknown charge and that's why my card was being declined. No receipts or documentation printed out of either machine. I asked my sister to pay for the {$70.00} taxi ride with her card since we had no other currency with us other than our credit cards. He scanned her card from the device attached to his phone ( also a keybank mastercard ). We heard a beep from the machine and he said it went through. Again, no receipt printed or any confirmation. Our plane was scheduled to leave in 1.5 hours. While in the airport we checked our online banking statements to find 3 fraudulent charges on our cards. 
2 charges on my card that was supposedly declined for {$3200.00} & XXXX. I called keybank as soon as I could on XX/XX/XXXX when these transactions were still pending. I was told they could not do anything while the charges were pending and I should call back when the charges are processed and file the fraud dispute, which I did. I have proff of these phone calls. My sisters transaction also went through for a fraudulent amount of {$220.00}. We were also charged associated foreign transaction fees with each amount. All these numbers were wildly inaccurate and the two on my card were DECLINED. I am attaching the statement from my sisters keybank credit card and my credit card with the fraudulent charges. 
Our cards were charged 3x for a total of {$3600.00}. I have called Keybank numerous times to no avail. I have asked to speak to a supervisor they tell me one will call. I have yet to receive a single call. I asked to speak with someone in executive client relations they assigned me a caseworker and that caseworker was to call me. no call. Every call I make to keybank i have to re-explain everything as if it is my first call. I have received one email response from keybank after i filled out a survey regarding my frustrations on XX/XX/XXXX. They reported that my dispute was not processed because the " merchant provided documentation that shows I authorized the transaction '' I asked to see this documentation. they have yet to provided it. We did not AUTHORIZE > {$3600.00} for a taxi ride. I have been a keybank customer for over 20 years as well as a mastercard customer for over 20 years. I have never had any issues such as this. 
I also found online the same fraud happening to another person which I will attach that article as well. 
I have filed a complaint with the federal trade commission who I have not gotten anything back from other than the automated response. 
I filed my complaint with the OCC who had transferred the case to you the CFPB however your company tells me they have nothing on my case.

I have also reached out to mastercard US who have also stated they can not help me. I am hoping you can give me some guidance of how to resolve this matter. I am supposed to have a XXXX liability protection on my credit card and this is far from that. I did everything i have been instructed to do to by my financial institution, they refuse to acknowledge this fraud or return my money.