unfairly treated by the college

I am a student at Mancosa and i have been treated unfairly by the college, mancosa never reminds their students that they have assignments to submit but they call everyday if your account isn't up to date. I wrote my first assignment and i submitted it on time that was in April then again i tried to attempt a KCQ assignment but i couldn't because the date wasn't due, on the day that i had to attempt because it was open for 24 hours i had a problem with loadshedding and i raised a query but they never responded to it then today i received my marks that i failed because of non-submission of kcq. i got 89% in exam and the final mark was 59% still failed. I asked for a second chance to attempt but they didn't respond. This is not the first time i had this kind of a problem and mancosa is delaying me to get my degree because am repeating a semester due to lack of communication and it costed me another 6 months. mancosa doesn't respond to my emails on time but when they money they call non-stop