Product: Credit card or prepaid card

XXXX XXXX I got a call from American express serve fraud department saying that someone tried using my card info at the XXXX in the XXXX. I usually don't answer phone calls that aren't in my contact but the caller ID showed up as American expresses phone number that appears on the back of my card so I answered they said my whole name and everything. The next day {$300.00} was taken out of my account ( {$290.00} for the actual transaction and XXXX for the pick up XXXX fee ) and I was completely locked out of my account. When I realized I was locked out I called the same number that was on the back of my card to get it unlocked and once it was unlocked I saw a transaction for a XXXX pick up that wasn't addressed to me or anybody I know. It was addressed to someone in Virginia. I called back and set up a dispute, not even a whole day later I get an email saying my dispute was denied so I appealed at least 2 more times the both got denied so I took my loss thinking someone hacked my account. Fast forward to XX/XX/XXXX I get a call from American express about the same issue and them saying that they were going to credit my dispute etc so I thought that was the end of that until I got locked out my account again so I immediately call the number that appears on the back of my card that called me earlier and they tell me to reset my password which I tried and when I got back onto my account almost {$600.00} two separate tansactions one being {$370.00} and another being {$200.00} was taken out of my account and is transferred to another amex account that I don't have/ know the person and they are also from Virginia XXXX note both people that I've talked to asked me the same information the the " official '' amex asked me. I went and tried to dispute that I also got denied but both times they never disclosed why I got denied and if I wanted to know why I'd have to write them a physical letter and wait. I ca n't drive nor do I have the materials/ money for it since the people who did this drained my bank account twice. A whole months worth of money gone. I ended up finding the CEO of American expresses email and sent him a message about the situation, I got transferred to a woman from the executive office and explained the whole story, she said that Serve was a collaboration between American express and another company and that she would ask the company why I got denied and why they wouldn't credit me back my money, I get a call a day before thanking. She tells me that they won't credit me because I gave what I thought to believe was The fraud department my information ( which they ask the same information when you call anyway ) and that it would fall under the category as a scam. I don't get why it would if they had the same number last time I checked you can't mask a number but you can mask a caller ID. I still have the call logs to prove it. When I called Amex and asked if someone called on these specific dates they just said " No we record all calls for safety procedures " so I'm thinking hmm someone there is using the same script, phone number and caller ID but I'm at fault? How would I have prevented that when they ask me my card information when I call them so when I get a call I think it's normal? It doesn't make sense.