I did a cabin crew t...

I did a cabin crew training and course at Damelin correspondence college I paid the full amount for the course only to find out that I wasn't to pay the whole amount because there are some subjects that I passed well in my matric year so I don't have to repeat them so Damelin has be refusing to give me my refund and it's been years now all they want me to do is to top up the refund amount so that I can further my studies with them and I am no longer interested because of their poor service so can you please assist me and getting my refund back because I have found a better institution to study at