Nedbank
Can't renegotiate even though I was promised I can

Hi

Over a year ago I renegotiated the interest on my home loan. I asked the call centre agent what I need to do to get a better rate. They said it depends on a few things and one of them is that I don't have a Salary Account with them. So to get a better rate I had to open a savings account and get my salary paid in it. The cheapest one I could get was the Savvy account at R90/month service charge and low interest. This account couldn't compete with my Capitec account (R4.50/month and high interest), but it was worth it because I'll get a lower home loan rate because of that.
I phoned the call center and asked them to renegotiate, only to find out that they don't do that anymore and that I need to remember the name of whomever I spoke to a year ago to be able to escalate this. I can't remember who I spoke to, so the can't help me. I basically lost a lot of money using a Savvy account vs a Capitec account on false hope.
Please help. I'd like to renegotiate for a better rate as previously suggested.