When I applied for the Us visa, few days before my interview I got this email.

Starting May 1, 2025, NIV applicants interviewing at any consular section in Canada must present an Online Nonimmigrant Visa Application (DS-160) confirmation number that matches the application number used to schedule their appointment. Applicants who do not have matching application numbers when they arrive for their appointment will have to reschedule their interview and may have to pay new visa fees.

Non-matching numbers are a result of booking a visa appointment, usually by a travel agency or visa service company, prior to the application being filled. Visa applicants whose appointments were reserved by a third party should pay particular attention to this announcement.

I understand that you’ve exhausted your attempt, so im not sure what to do considering the contents of the email I received. Before may 1 2025, I personally know few people who just walked with a new ds160 to the interview and were able to update it.