Request For Booking.com Cancellation Confirmation Number & Processing

I booked a United Airlines ticket through Booking.com on 1 June for travel from New York to Chicago and later requested cancellation. However, I have not received any official cancellation number, written confirmation, or proof that the booking was cancelled. I contacted support and also used the OTA support number 1-844-587-34** for assistance, but I still need official cancellation confirmation directly from Booking.com. I request my cancellation reference number, written confirmation, cancellation document, and prompt processing of any applicable refund to my original payment method. This complaint description follows standard complaint-writing practices of being clear, direct, and including the requested resolution.