You can try to access the official link https://education.oracle.com/OUcontactUs on Order Processing. Either Order Information or Invoicing
I tried last week but Oracle can't solve it without some order related record.
The funny part is that the Payment Hub does not keep any data related to the order of the company which it provides service.
In the past I had a similar problem with Paypal but they resolved it automatically in less than 24 hours.
Despite everything, I hope that you are successful in the purchase and in the other steps to achieve your certification. Success on your journey!
My bank solved the problem today. Thank God.