Product: Credit card

I had an American Express card since XX/XX/XXXX (? ) and had NEVER missed a payment. in fact, often I would pay 3-4 times the requested payment. 
Even when XXXX I NEVER missed a creditors payment. And I am NOT on auto-pay, so I take my credit worthiness very seriously. 
In XXXX XXXX I was notified by American Express that they were raising my credit limit due to quality of handling of my account. I did NOT ask for a credit increase. Then 2 days later I get a letter telling me my interest rate is going to jump from XXXX to XXXX because my credit card balance is too high?? I called to challenge the rate increase. I stated I need to close my account. Tech sent me to a supervisor named XXXX ( XXXX xt XXXX ) who stated they would hate lose me and she understood why I would be frustrated. She suggested I call her back in XX/XX/XXXX and she would try to help me keep my rate as it is as they would n't want to lose me due to my long term relationship. Although I had cancelled my account, she stated I had up to 90 days to request a reinstatement. Now keep in mind, they did n't cancel my card, they just doubled my APR. So I work for the military and I leave for XXXX and come home. Being financially saavy I came home and was taking advantage of a balance transfer from my XXXX XXXX which would change my APR from XXXX on AMEX to 0 % for one year on XXXX. Since I had cut up my card after the first call, I called to get the cc number and was told that they could not give me my number because I cancelled my account,. Then said it was because they never give out cc numbers over the phone. Then the manager told me my monthly statements would no longer be protected and they would be mailing them again. All the time, I was professional but frustrated. ( I was told these calls were recorded, so it will validate these statements ). I requested my card be re-opened and was sent a letter telling me that my request denied due to my credit balances. I am not going to try and challenge the auto credit scoring, but my relationship and payment history are my proof that this made no sense. Remember AMEX raised my credit limit, not at my request. So, I contact XXXX and she also states that if they declined it she would no longer re-open it. I believe this is retaliation for challenging the letter. Let me make it clear, i have NEVER been disrespectful to any AMEX rep as a result of the credit policies. These are people just like me. But I am a business professional and will not allow businesses take advantage. So lets summarize : Credit relationship with AMEX - AWESOME Credit card payment history - EXCELLENT Professional communications - EXCELLENT Credit History with creditors - EXCELLENT So what was explained to me by XXXX is that my APR was being aligned with others in my situation ( See above ) although she understood my reasoning which is why she said to call her back and gave me her direct line. 
So, at what point did AMEX now think I was not a good candidate to carry their credit card? Before or after I challenged the APR increase. XXXX to XXXX? So they took retaliatory action against me. In the end, cancelling the card could have an impact to my DTI causing other creditors to raise rates.