Does anything get done?

I have a home loan with Standard Bank. I have been a loyal client for about 20 years. I've been asking for a concession on my home loan interest rate for about a year now. Every time I speak to someone from the call centre they tell me I can speak to a specialist about it. Then they themselves come back and say it cannot be done. So now I have looked elsewhere for a better deal and I got one. I forwarded the letter of acceptance to the bank on an email address I got from a call centre agent and not a word! I'm not sure if anyone even checks this email address, but already thinking of the generic response I will be getting from the call centre discourages me from even calling to check up. How can I work with this?