Sick of this company

I am now fed up. I took ouy a loan by supreme finance valhalla centurion. Thet did not even try to debit ky account and now when i went there they say its my problem with interest and i should've come earlier. Excuse me you are the finance provider im not supposed to run after you I WILL NOT PAT ANY INTEREST I WILL PAY MY LAST AND FINAL INSTALLMENT AND THATS THAT. I DID NOT EVEN GET PAPERWORK WHEN I TOOK OUT THE LOAN SO I DID NOT KNOW IF IT WAS A THREE OR FOUR MONTH LOAN THOLANI AT THIS BRANCH IS RUDE AND HE IS THE ONE TELLING ME ITS MY PROBLEN AND THE INTERST WILL JYST BUILD UP. PHONE ME AND SHORT OUT THIS NOW...