I worked but didn’t get paid?

I worked at a big corporation. Long story short they were trying to deny people the use of the bathroom, unless they were on break. I didn't like how they were running things, so I put in my notice. I looked at my last pay-check, it shows I did not get paid for my last 2 days. I thought maybe that was a simple mistake and it would come on the next pay period. It did not. That day, I emailed HR and the store director that I did not get paid for time worked. I got no response. Because of not getting paid I was not able to pay for my oil, I ran out in the middle of a big snow storm. I had to ask for help from others to be able to pay. This put a lot of strain and distress on us. Advice?