SSDA is a ********** collection service!!!

My Edgars account was handed over to SSDA for collection as I was unemployed for quite a few months. When I got a job, I called them to set up an arrangement for them to deduct monthly from my account and all was well until recently. In the beginning of January 2019, I called to request a balance as I knew this was the last month I would need to make a payment as I had planned this when I made the arrangement, on the 4th of January 2019 I was told my balance was around R600 and that the amount the debit order at the end of the month would be around R650 to round it off because of the relevant collection fees and that was absolutely fine with me. Subsequently on the 24th I received a call from a consultant to confirm that the debit order would go off the next day but the amount that was to be deducted was way off because she said they would deduct R1 000 as per the initial arrangement but when I asked her how that was possible she said that she didn't know because my balance was R1 759 on her side and that she would listen to the call I had made on the 4th and get back to me, I am yet to receive that call. Anyway luckily I had requested a statement on the 4th which indicated my balance. I went through my emails and retrieved the statement and called SSDA several times to make enquiries about my problem, every single consultant I spoke to said that they would call me back after listening to the call from the 4th, not one has gotten back to me, eventually I requested to speak with the team leader, Allison, who bluntly told me that there was absolutely nothing she could do but requested that I forward the statement to her so that she could look into the matter, she then promised to get back to me the same day, I am still waiting for her to come back to me. Anyway the debit order went off on Friday, I reversed the transaction because I refuse to pay more than I need to. This is really an inconvenience for me because I had made plans to clear my credit record but how can I when SSDA is adamant on making pay more than I have to?? I am seriously angry and I feel like all those payments I made previously were in vain. If SSDA cannot resolve this issue then I would like for them to pay me all the money that I've paid thus far because it was all in vain.