Discount not allocated

I enrolled my son into the 1year Higher Certificate in Game Design and Production course in December 2022. I received an email from SAE stating that if I pay a minimum deposit of R5000 before 31 December 2022, I would qualify for a 10% discount on the yearly course fees. Which I did. Yet, on the 12th of July 2023, upon receiving my statement, I noticed that I was still being billed for the full course fees. No discount as promised was allocated. I sent an email to SAE Rosebank on the 14th of July 2023 questioning why the discount was not allocated. Never received a response. This was followed up by multiple emails eventually also emailing the Academic Administrator, Managing Executive of the JHB campus and the Head of Academics, and the only response I ever get is that the allocation of discount is in process. My question being, how can it take 10 months to allocate 10% discount? Not receiving any joy, I emailed the Academic Head of SAE, which is part of Invictus Education, on 13 October 2023, requesting an updated statement with the 10% discount allocated. Unfortunately, once again, I was only told that they would investigate as to why the discount was not allocated as yet and will get back to me as soon as possible. Today is 17 October 2023, and once again I had to email following up on my request. No feedback whatsoever from SAE. I find it quite disturbing that in institution such as SAE would treat their sponsors this way. If I was asking for something unreasonable, I would understand their lack of assistance. But, I was promised, on email, a 10% discount if we paid before 31 December 2022. I kept to my part of the agreement. My question is, why cant SAE? Why is it so difficult to allocate the 10% discount? Why does it have to take 10months???