Amex Credit Card Complaint

Amex Credit card department,

Credit line increase/decrease Florida

I applied for a credit line increase with AME- during - 2016. When they responded they did not give an exact reason why my credit was declined. I have contacted them several times by phone and in writing asking what specific reason my request was declined. They have never responded to any written letter ( - letters ). I have asked for the name and address of the credit bureau that was used in this credit making decision. They have never reported this information to myself as required my U S Laws. please ask them to respond to my letters and give me the name and address of the credit bureau used in making this negative credit decision.