No response to a investment complaint

On 11/3/2013 i invested a substantial amount of money with FNB. My instruction to their rep was a low risk monthly sustainable return. Instead i got an inflation 1 return minimum investment period 3 years according to the rep. The rep retired a few months later. The investment is currently yielding a third less than it did at its highest point. I filed complaints at the Bluff Branch but was told that there was nothing that could be done. I only received compliance docs from the rep. There are no penalties indicated in case of early termination. I was told by the Bluff Branch that penalties are 5% of the investment which has since increased to R140000. I was recently contacted by a Henko from the Brandwag Branch asking me to collect the investment certificate over 2 years after the initial investment. He committed to looking into the matter over 3 weeks ago. I have not heard from him since. I am not enjoying the full benefit from the investment of my own money but i guess someone else is. FNB is refusing to amend the investment conditions or allow early termination without imposing ridiculous penalties and it looks as if i am stuck with this pathetic investment for the full 3 yrs