Short version:
- saw a great offer and tried to book a ticket
- instead of successfully booking - i was redirected to the main page and got various errors
- never received confirmations or anything else that would indicate a succcessful booking
- I was disappointed not to have gotten the tickets, so I decided I will try another day with a different airline
- I got a great deal on a KLM flight (which uses a delta plane on one of the legs of the flight)
- 4 days later I suddenly noticed credit card charges for 1000 Euros
- Delta had charged me for 2 tickets
- I called delta and they said they understood, but will only refund 1 of the tickets
- they insist because the KLM flight is 3 days earlier than the flight I had tried to book on the Delta website, they cannot refund both tickets
- they will take 2 weeks to decide if they will refund me for the other ticket
- Visa said talk to Delta

What do I do?
- I have no desire to pay 500 Euros for what essentially amounts to air
- I have booked dozens of flights and know how to use a website - it was clearly an error on the website
- to this day I still have not received emails, confirmations or anything to the flights that I apparently did buy (yes, I ckecked my spam folder as well)
- It was clearly their error (no emails, website errors), but I feel like I have to ask for leniency and beg for my money back
- i am afraid that should I refuse to pay that I could have problems with my KLM flight that is partly operated by Delta

Do you have any suggestions or advice for me? I am not quite sure how to proceed.
I do not want to get debts or make the situation worse- but i donīt want to pay 500 for absoutely nothing

Thank you!