Bad Customer Service / Response Time

I have been requesting to change a Debit Order Date for my personal loan, since my salary date moved by a few days. Since I do not have the time to go to the bank within the times they trade, I was told to contact the contact center as they cannot assist me via email for security purposes, which I can understand. I phoned a couple of times for a few days, holding on the line for 20 minutes or more, with NO SUCCESS whatsoever. I emailed them again explaining that there has been no success with my request to change my Debit Order Date. No response. I emailed again to follow up on the matter, still no response. As a professional company that advertise themselves for great service - I would not expect this POOR SERVICE!