I need to know how I can get the average computer salary as desired.

I am a noted as a Computer Operator Class B, by one section and Class 1, by another section. I've brought this to my manager's attention during my review. I am being paid way under the Computer Operator salary that I have found information about on the network. My boss tells me that because of the way I was hired in that is why I'm being paid so less. I was originally started as a print room operator, which at which point has classed me as a Computer Operator C, which is the lowest class of the Operation. I've been on my job for 5 years and for the last 3 years I have been promoted from the Print room into the Console room area at which time they have made me an Computer Operator B. Is it right for my manager to keep my salary way under the average computer operator salary even with the experience that I have now accured since being in this position for 3 years. He states that since I was hired in under the minimum that the recent raise that was given to me was appropriate and it still is way under the average computer operator 1 salary. What can I do about this situatuation.