Universitetet i Oslo

I have applied for norwegian summer course and applied my documents before deadline 23/4 and then sent an email asking if there are further documents needed, instead of pointing out the rest of the documents needed, i have been told to go back to admission link which wasnt much of help from their side.
A month later i get to know that my application was denied due to some missing documents and have been told to wait for fall semester to register again as i have missed the deadline date for uploading my documents....
However, im still in contact with admission office to know why i was not qualified for the language summer course, they tell me that they have sent an email to me on 23rd telling me to upload more documents. Now i have checked all my emails and i can not find that email on 23rd they are talking about.
I wrote another email saying i havent received the email but i got a reply for my email with an email saying: as i mentioned before you received an email etc...., i did everything the right way and even emailed to ensure i have uploaded everything needed.
Mistake was not from my side as they claim i have received an email that i havent received. Its very disappointing planning my summer for the course that i wont join due to a mistake caused by the university and im blamed for it as they wont accept the fact that its their fault.