Can I sue this organization for emotional distress?

I've been getting harrassed by staff at a retail store near me for about a year now...and nothing has been done to correct their behavior. I've been getting verbally assulted, purposely underserviced and i've heard staff make physical threats about me to each other under their breath. I've been working with the upper level management for some time now in an effort to resolve the situation...but they have not fired or repremanded any employess yet. Can I sue them for emotional distress..i've been having nightmares, stomach cramps, heightened levels of general anxiety and bouts of depression from the abuse. What can I due legally towards them? What retributions can be handed out? What monetary (if any) damages can be paid towards me? How hard is it to find an attorney to work on a case like this "Pro Bono"?