Postgraduate degree urgent help

I have applied to study MSc financial management at UOB last month. One of the lecturers that has agreed to do my reference has only done it two days ago, I had no way of contacting him. I got told last night that I haven’t been accepted, as I need economics or mathematics or some of the following modules they listed for my undergrad (baring in mind in first year I got told that as long as I have some finance related modules I will be fine). It is too late to apply to something else, if he has done my reference earlier I could’ve found out earlier and applied to another course. Is there anything I can do? Do I have a ground to stand on? Please help guys x thanks

If you have the advice they gave you about being fine with a few Finance modules in writing, I would forward that to them and ask whether you might be considered for another course instead.

That’s the thing I don’t have in writing

what about the lecturer delaying my application

In that case it's going to be your word versus theirs. The onus is on you to consider whether you have a suitable background before you apply. Assuming this is the Uni of Biringham, this is what they currently say, (emphais mine):

"In order to be considered, applicants will have or should be expecting to achieve an Honours degree (2:1 or higher) or postgraduate diploma from a UK university (or overseas equivalent) in a highly quantitative subject.

Applicants must have achieved a mark equivalent to a 2:2 at undergraduate level in Mathematics or Mathematics related modules. If necessary we will assess the academic transcript for performance in Mathematics and Mathematics related modules. A minimum of GCE A-Level grade D (or overseas equivalent) in Mathematics, Applied Mathematics, Further Mathematics, Physics or Statistics may also be considered to meet the quantitative requirement."

Doesn't sound like it affected the outcome. Nothing you can do about it in any case.

So what if the lecturer took ages to reply? This has affected me being able to apply for another course because if I found out earlier it would’ve been easier to apply for another course this year