u/Jalen-_-6

I'm a 19 year old who's recently joined and jumped into the field, I got into a local shop (PEPBOYS) behind my house funny enough, they first told me I'd be getting paid $19 an hour. Fast forward literally a week I was told I'd actually be getting $15 an hour after I already started there... So far I've been in here for a month and I'm just wondering who exactly do I contact about this? I'm actually about to apply elsewhere soon but I feel as if I'm owed money that was promised to me. I have a neighbor who worked here right before me who had left and he said they did the same thing to him and once they no longer needed him they dropped him. This can't be legal