Bad installment

I opened an account in December 2024 and bought a fridge. I was required to pay R687 for 36 months and then I opted to pay a R1000 to shorten the payment period. I started paying in January but, however, my balance has been stuck on R7000+ despite the R1000 versus R687 monthly payment. I went to the Tlhabane square branch and up until this day nobody has given me a proper explanation as to what is happening instead, one of the employees told me to pay the R7000 amount in order for me to see progress and she was very nonchalant about it. I will never bother myself with that store ever again, it is literally the worst furniture shop to have an account with.