FNB fails to address my complaint.

Following my previous complaint on hellopeter, FNB sent me numerous messages about how my high priority complaint will be addressed by someone phoning me within 48 hours. In the interim they sent me new forms, and once i returned those, I again got the message I would be contacted. Ive responded to each message, it's weeks later, and absolutely no other comeback from FNB. I am exactly in the same position as I was months ago. What on earth do I do now?,