Unfair business Practices

My child is being rejected at the creche where he attended for a year because I delayed with last year's fees R1200 which I paid in full today. The owner says the child will only be allowed back after paying full year's fees amounting to R9300 at once. This means the monthly option on the admission form is null and void. My child was burnt by hot porridge in October 2019 and i suffered medical expenses without the creche 's help. My child spent almost 2 months not being able to attend creche due to his injuries and I have not considered the legal route as I thought this was one of the unfortunate accident only to be treated badly now when my poor child has to go back to school. I am in a position of the letter from creche that explains how my child was burnt and to me this was just confession of pure negligence and none of the employees was taking any responsibility. If there is anyone who can assist with this matter please assist me.