Product: Credit card or prepaid card

My name is XXXX XXXX and Ive been a cardholder since XXXX, Id like to address an urgent matter that is frustrating treatment by American Express that is beyond unfair. 
In XXXX, I booked a reservation and cancelled this reservation at a hotel to celebrate my mothers XXXX birthday in XXXX XXXX. My mother opted for a different hotel and within time limits I cancelled the original hotel, a Hilton brand. For some odd reasons unbeknownst to me the Hilton brand hotel was allowed to charge me {$10000.00} even after they confirmed cancellation. Additionally, I shared the cancellation email as proof with American Express.. To continue, the charge was never released from my Platinum card on the back end and I was charged {$10000.00} on my card for months. I filed multiple disputes and ultimately contacted XXXX; filed the proper paperwork for a mediation with American Express over this charge and balance. 
When filing the mediation I noticed on the back of the statement, the contact and procedural information for mediation was incorrect. By estimated calculations nearly XXXX XXXX of your customers regularly received wrong information on how to file and conduct a mediation with American Express. One or two cycles after I reported the inconsistencies to your legal department it was then updated on my statement. 
After I conducted mediation with American Expresss general counsel, we agreed Id pay what I owe and not {$10000.00} for a hotel I canceled. I was then reinstated and given a {$4000.00} limit over a year ago. I still pay a full membership fee for the card and Im unable to freely travel internationally with a {$4000.00} limit. To date Ive charged {$48000.00} to the card. Last year, I had large medical expenses and in the midst of an already stressful and painful ordeal I had to -sit at the billing office charge {$4000.00} ; -wait, pay the {$4000.00} charge, processing a payment to Amex -wait for that payment to clear ; -charge an additional {$4000.00} of medical expenses - repeat to cover a {$10000.00} charge at the medical facility. 
I had to do this over and over again in this facility on different occasions. I was deeply embarrassed and only lucky I was on WiF to make such transactions. In another similar situation I would not have been able to make the full charge as needed or be allowed to make piecemeal payments for a single transactions. 
Ive maintained my standing with American Express, Ive paid all bills on time and have had no issues besides the {$4000.00} limit. 
On XX/XX/XXXX, I requested with Amex Customer Service to have the limit removed as I plan to travel internationally over the next three months. It was declined based on the type of card I have with Amex. I was never made aware that after the mediation and report of inaccuracies that I was reinstated with a different type of card. I then applied for a new Platinum card and also made a full billing payment on the same day. Days later I received an email stating my bank account could not be located. I immediately contacted my bank and they reported no problems with my account, routing number or balance. There was no reason for American Express to not locate the account. I then processed the same payment three times. On the third time the payment goes through to my XXXX XXXX. Nothing on my end was changed. Nothing on XXXX XXXX was changed. I follow up w the status of my application and it was DECLINED due to returned payment. I could not believe this, it was very upsetting and feels like a game is being played here. I spoke with someone at Amex and for the sixth time confirmed my banking details and she replied that the system kept changing my routing number and she could not explain why that was happening. She explained the steps she takes to confirm payment details, she can see my current banking details but the routing number keeps changing to a different state that is not NJ. The agent made some sort of fix and explained I should not have this issue again and she had no real explanation for it. Its my assumption my card application and bill payment on the same day caused some technical chaos. 
I call back to the application status line after speaking with the payment agent and Im told my application was declined due to returned payment! This is truly unbelievable and I was told to reapply in 30 days. I am beyond livid and want to cancel my card. I can not take this treatment from Amex, it disheartening. 23 years Ive been a member and in the last three Ive been mistreated. 
I did not return funds. My bank account is active and locatable with zero reported outages or issues with XXXXXXXX XXXX. The funds were ready and available for payment. My due date is XX/XX/XXXX and I paid on XX/XX/XXXX to maintain good standing. The XXXX XXXX account number with Amex is correct. The routing number with Amex is correct. Why was American Express unable to locate account? 
Ive had no problems ever with making a payment. This error on XXXX technical side was used to make a decision to deny my application. This is baffling. Why am I the subject to being maligned? 
Id like to have the limit removed from my card or given a new card with the full Platinum status that is acquainted with the annual fee.