Product: Credit card or prepaid card

I was hired by a company out of XXXX XXXX XXXX known as XXXX XXXX XXXX XXXX. They were registered in the state of New York and at XXXX I had applied for easily XXXX jobs and had been turned down for all of them. XXXX XXXX XXXX hired me and I desperately needed the job and money. They sent me a formal packet of information totaling some 20 pages of information about the company and the benefits the job etcetera. It all looked very genuine I filled out a payroll form, provided my tax ID number so I could be paid and thought all was well. During the first two weeks I was on a trial basis, and I had to purchase the items which was my job using my own credit cards, per my contract with XXXX XXXX XXXX, where XXXX XXXX XXXX XXXX wrote 3 checks to American Express to fund the purchases. Therefore, they had my credit card numbers and my Social Security number. They sent three checks totaling {$150000.00} to American Express the last one being supposedly for my salary, expenses, goods purchased and shipped, bonuses and commissions. 
I specifically requested that they send the check for my salary and bonus to me but instead they sent it to American Express who received it on XX/XX/XXXX. They sent it to one of my credit cards which created a credit balance equal to the amount of the check of {$52000.00}. I was starting to get bad feelings about this organization so I changed my credit card numbers and closed this account and onXXXX other. Before I did that however I verified on numerous occasions that American Express had collected the funds and that they were good. I then closed my account and American Express sent me a check for the credit balance XXXX. I received the check around the XXXX of XXXX and put it in my account as it was to be my pay. On XX/XX/XXXX American Express sent me an email saying the check was dishonored and American Express then proceeds to start coming after me for the money, negatively impacting my pristine credit report and refusing to do what they should have done which is return the item to the bank and get the money from my former employer who are the ones that owed it not me. I have hundreds of documents relative to this situation but American Express refuses to # 1 return the item and do what they should do which is credit my account that they assigned to me and # 2 quit negatively impacting my credit report and saying that I am delinquent when in fact I do not owe them the money. They are killing my good credit that I spent XXXX to 40 years building up. That's the short version of what happened. I want American Express to act like a big bank and return the items that were charged to my account as they are totally unauthorized as I had nothing to do with sending the original checks nor returning the items to be charged against me account after 23, 32 days., and 3.5 months later respectively. 
Also, I have requested of American Express to send me copies of the complete checks the three items that they received from the people perpetrating the fraud so that I could pursue them or give it to the authorities to do so and they have refused to do it. Instead what they have literally done is joined in perpetrating the fraud on me by preventing me from having the information I need to find these people and then telling me to t talk to them and get them to send American Express the money, that is ridiculous. The phone numbers and the address of their business were legitimate when I checked them out however they are of no use now. They had bank accounts where they issued the checks from to American Express and who should be accountable for those checks and that is who needs to be dealing with this not me. I was a loyal card holder of American Express for over 15 years and I thought they would do the right thing but they have not yet done the right thing which is to charge back the items to the banks that dishonored them, the fraudsters. I have spent literally XXXX hours on the phone or on my computer dealing with AMEX and have gotten nowhere. I have even contacted the executives and I've been ignored. This is all the money I have, I can not lose it.