Bad service, no willingness and costistency

Sometimes consistency is very important to clients I have app**** for the Revolving Credit plan with Standard bank and was approved for what ever the amount, but I was not happy about the rate that was given, so I have escalated the matter but there was no willingness to review the rate. The reason for a decline of rate review was told that my income is too low for them to assist , so to me I doesn't make any sense why the clients will be charged the rate based on their income instead of risk view. the sad part is, I have already an existing client with Standard Bank over 5 years and the product that I currently holding the rate is much reasonably.