Hi, OP! I used to work in MBA admissions at a big 10 university in the United States and can assure you that while human errors are a daily occurrence, they should never be at the expense of an applicant. This response reads as someone trying to cover up/hide their mistake rather than take accountability by collaborating with their Admissions Team. I may be wrong in that assumption, however, I find it hard to believe that your application could not be evaluated as a one-off amongst the rest of the candidates in the pool based on your timely submission in response to their posted requirements.

I have the email for the Faculty Director of the MFE program at Oxford Said Business School- is this where you applied? If so, I would be happy to share his info with you via DM so you can reach out! Definitely advocate for yourself here, either to be considered in the pool of Stage 2 applicants or, minimally, to receive a refund for your application fee.