Sheet Street Account

I have an account with sheet street with an outstanding balance of R5323 which i made an arrangement of R1000 every month since my account went into arrears due to Covid 19 lockdown salary cuts. I have been struggling financially during the pandamic. I paid R1000 in December and again in January 2021 i failed to pay end of February as i was in Isolation due to Covid and my salary did not allow me to pay however in stead of the ammount decreasing it has increased to R6144.23 i requested for a settlement discount as i want to settle the account but am told that they can not give me a settlement discount. I need to try and get my finances back on track what can i do in this regard as i can not afford the whole balance and what happened to the money i paid because this account keeps on increasing