First, email firstname.lastname@example.org to confirm whether your CT has been uploaded or not. Email is the preferred communication method for this as multiple people in B&AO upload CT's.
If your CT was uploaded and posted to your budget (check MyFD to verify), submit the same CT and make the dollar amounts negative. Do not make any additional edits. Once your reversed CT has been submitted, you can submit a new/corrected CT to be uploaded.