Emailed the GS desk asking to process a refund for 3 reservations that resulted in ETCs back to the original form of payment. Instead of doing it for me, was provided with the following:

Please visit united.com/refunds
Select Request Refund
Add all required information
Under purchases > Enter Receipt details
Customer should enter their ticket number in the 'Document Number' field
In details reason for request > "Cancel ETC and refund to original form of payment"
Enter email address
Submit

Great...... thx much.