Product: Credit card or prepaid card

Hello, I was trying to purchase airline tickets for a month and luckily found good price on XX/XX/XXXX. I wanted to buy the tickets using the XXXX airline website and they were advertising a promotional offer of {$400.00} statement credit and XXXX bonus points to open American Express XXXX XXXX. 
Since I have an excellent XXXX XXXX I attempted to applied for the card to take advantage of the promotional offer. 
So therefore, I started the credit card process prior to purchasing the airline tickets so that I can take advantage of the offer. I was able to qualify for American Express XXXX XXXX and the website approved the cards. I waited for few minutes to receive temporary credit card account number so that I can proceed with the tickets purchase but that did not happen. I never received any emails with the temporary account number. 
Waiting after few minutes, on the same day XX/XX/XXXX I called American Express XXXX XXXX and was immediately transferred to a representative who informed me that she do not have access to my credit credit information and that I must wait to receive the email with a temporary account number. Knowing that the ticket price will expire in few minutes/hour, I called XXXX airlines and the wait was XXXX hour and XXXX minutes by the time. 
By the time I got the customer representative on the other line the ticket prices were already expired and were showing much higher prices than before. I explained to the representative that I wanted to make the purchase using my newly applied American Express XXXX XXXX account to take advantage of the offer but have not received the temporary account number to proceed with the purchase. She asked me the details regarding the date of travel, flight numbers, destinations, booking class and said that I can make the purchase on any other card on hand and still get the current offer. So therefore, I proceeded purchasing the refundable tickets fare online at much higher prices since the good prices were expired due to all the delay I encountered with the wait time to speak with an American Express and XXXX airline representatives. 
On XX/XX/XXXX I called American Express XXXX XXXX inquiring about my credit card as I only received the secondary member card and not my primary card, and they said that I would not receive a temporary account number via email due to security reason and my credit card is still in transit and will not receive it until after a week. I asked her about the promotional offer stating whether I would be qualified to receive the {$400.00} statement credit as advertised and she said the I would not be qualified since I did not make the ticket purchase using the card. She recommended that I call XXXX XXXX to see if they can cancel my transaction without any fees or penalty and that I buy another tickets with American express credit card as the prices were same. 
On XX/XX/XXXX I called XXXX XXXX and the wait time was XXXX minutes, the representative said that the tickets I have purchased are not fully refundable, although it clearly stated that the fare I purchased is refundable. 
I am in a very frustrating situation as I only got entice to open American Express XXXX XXXX credit card due to the {$400.00} statement credit. If I had known that they were not providing me with the temporary credit card account number I would have not applied for the card. 
Bottom line, my credit score went down due to new activity, bought the airline tickets at a higher price as the prices were expired by the time I got to speak with a representative, I can not get full refund on a refundable tickets. 
In theory, I lost the {$400.00} statement credit and also bought the airline tickets at much higher prices, lot of misleading information from the representatives, delay receiving new credit cards and the long wait times going back and forth trying to sort this matter but everything to no avail. 
All I would like is to get {$400.00} statement credit as advertised. 
Thank you for your time.