Extremely high and ridiculous interest rate. Never apply for a loan here no matter how desperate.

my first installment was in December 2018 for a loan of R8000, so which means I have paid for 7 months already an installment of R606.66 = R4246 and yet my current balance is still R7005.75. this is a ridiculous amount meaning by the time I finish paying off this loan it will be over R14000, am I missing something here? if these interests were explained from the beginning surely I wouldn't have taken this loan basically its like out of this R606 Im paying less than R300 beacuse if it was R300 surely R2100 was supposed to be paid up by now.