POOR FEEDBACK FROM NEDBANK HOMELOANS

Called the home loans c/c this morning ref. number ***5. reason for my call was that i have put a 18.8% deposit of my home loan when it was approved by nedbank a year ago. From a blog i was reviewing i realized that a lot clients that have home loans with nedbank that even put deposits lower than mine received excellent rates below prime rate eg -1.%-1.25%. I have a clean and clear ITC record before then and until now and i wanted to know why i had a rate of prime +0.5% . The agent was very unhelpful and said that i should have negotiated then when i took the home loan rather than calling now. i asked her if there is anyone else that can assist me because she is cutting me short. she said i must go to the bank and fill out an application form. i then asked her how the process works after the application and she says she doesn't know the process and was very unhelpful and i was annoyed as this is a call center for home loans and queries. Please can i have somebody who is clued up to call me to explain the process. Thank you.