Dollar Tree

I am an ex-employee of this Dollar Tree I had been working here but a short while and many days I worked for other people and I don't feel I got the pay I deserved for working shifts that weren't my own I would receive either the same amount of pay or even less money and that's not right it's actually very wrong. I never received proper payment at this job and all I'm asking for is a complete and full backpay in the full amount of the days that I worked for other people that never showed up on my previous paychecks so I won't have to contact my lawyer to seek legal action.