Callcentre cyber bulling

A couple of months back I took out a short term loan with capitec, during one month I wasn't able to make payment which I then asked for an arrangement to increase the debit amount due and split it with the remaining months. That has gone off as arranged but I have been receiving multiple calls from the collections department for no reason as my instruction still stands. I have visited the kolonnade branch numerous times and the call centre agent confirmed that everything was fine but there was no way to stop the calls. I am down to my last month and I have just had enough of the automated voice mails to contact capitec and cyber bulling of different call centre numbers calling me. I am disappointed that there is really "no way" to prevent these calls. Having worked in the financial institution there are card notes that can be placed and viewed before calling clients, or rather getting a better system to prevent this from happening.