Unfair charges

I made an arrangement for an account that owed R830 in July 2022,a debit order of R100,this morning I call SSDA for a balance on my account I aas I want to settle,I am told I owe R250,I don't understand how as I have paid R100 via debit order for the past seven months July 2022-January 2023,on top of it I am told it adds up to R302 because I called their office how does this work?can you please help me?