Incentiv8 made a decision about my how I receive my money without informing me

I joined Incentiv8 in 2019 and this year I'm supposed to recieving my graduate payout in a lump sum of R12 000 but they are now telling me that they will give me in installments of R1 880 for 6 months which was never an agreement. They decided on their own without informing me or asking me if that's what I want. how do they decide that with my money. please somebody help me, I'm graduating July and this money was supposed to come to my aid.