Disappointed student

. I have completed my 2nd year but am awaiting my results. In March this year I made an error and submitted an assignment that was due the first week of may instead of the one due in March. It was an oversight on my part. 13 days after the assignment was due (on 11 april 21) I received an email stating I had not submitted my assignment. Initially I was confused as I remember submitting but when I went onto the portal I saw my error. The email sent to me by regent stated and I quote "if you have not utilized your two assignment extensions for the semester you may use these, otherwise a late submission fee payment of R750 is applicable. Note that the portal will close for submission for this module on the 12 Apr 2021 " I had not used my 2 extensions and as per this email knew I could upload my assignment however when I tried to the portal would not allow me to as you have to select that a late submission fee is payable. You have no option but to select this as you cannot upload the assignment otherwise. So I did so as I was not prepared to not submit and potentially not be entered into the exams. I received an invoice 2 days ago stating I owe R750. When I questioned this and pointed out that the email sent to very clearly gives me 2 options, that being use my extensions or pay and since the extension was not working on the portal I selected the pay option simply because there was no other way. I then get told the extension in this case is only allowed for 5 days from the date the assignment was due!!! Now I have used the extension in my first year so I know how it works. This was not stated on the non submission email sent to me and I find this extremely disingenuous on Regents part. How can you send a student a reminder 13 days after the non submission knowing full well that their 5 day window period had passed and they have no other option but be forced to pay?? Had I received a reminder within the 5 days allowed as they have now told me, I would have immediately uploaded it as my assignment was done. Highly disappointed student