Absa refuse to reduce my car installment

I paid a lumpsum of 100000 to reduce my monthly installment.this happend on the 28 October 2024.i have sent several emails to request for a reduction and i have also made several calls were i got numerous ref numbers.everyday when i follow up with them to check the reduction, i am told about a system error and they cant reduce my installment.I feel someone is not doing their work and as a result i hv2 suffer.i received my statement on the 11 and nothing has been reduced.such service is very dissapointing