I'm very sorry to hear about your situation.

Can you go back and find the charge on your credit card statement? Some credit card providers (Amex comes to mind) include the booking reference in the extended line item data for a particular purchase, which you can easily access online. For Amex, just click on the charge description, or the > on the far left hand side of the charge description, next to the date. The booking reference should be listed under "Additional Information".