FNB Promises. Absolute Nonsense

How can an organization just completely dis-regard a client's bad experience with their business practice?! I am so disappointed with how FNB has handled my issues with them. It has been over three weeks since I wrote about how their relationship center's lack of response & nothing has changed. I wrote a review about the business practices if FNB of making promises that are not kept in order to attract clients. I was promised a reduction on my interest rate which has not happened to this day. the only time that communication was established, was when FNB wanted to close out the issue that I raised about them not keeping their promises. They still haven't kept their promise, their communication & service is still pathetic & I still have not received the interest rate reduction. My question is, what do I have to do to get some answers from FNB?