Pay Now Or

I was supposed to pay the installment and the outstanding R7500 of which I made a promise to pay so that there won't be an arrangement outstanding. Unfortunately I only managed to pay the installment , today the lady called and said I'm a high risk there is no arrangement that will be put in place for me. I tried to explain my point in making that arrangement of paying the total outstanding, she kept on asking where is the rest of the money. Problem is I got paid a salary plus a bonus, so my bonus was less and I could not pay the total outstanding. All I am asking of them is to split this R7500 in 3 installments, instead of handing my account to legal whereby they will repossess within a week. If wanted to lose this car I would have not paid a full installment or would be more than 3 months in arrears. Now I owe 1 installment and willing to pay but she does not want to give me a chance. Please help already paid 8 months I can't lose it now.