Graduation fee

I would like to express my dismay with Regent Business School. I registered for the postgrad diploma course which i paid in full. I have mot been able to get them to send me my postgrad diploma although i passed the course. In fact they have ratger debited my account with a fee for graduation of R450. I have been trying to get them to remove that fraduation fee but without any success. i did not even attend the graduation. Another point is that the graduation was during the height if the Covid pandemic. Please assist me in getting Regent to take that graduation fee off my account.