Dollar General Sales Associate/Cashier interview questions

I brought my resume in, and filled out an application in store. The store manager, at the time, was overly excited to see that I had quite a bit of retail experience. He interviewed me, and hired me the same day.

I did all the talking. I gave a detailed description of all job functions I have experience fulfilling. Manager hired me on the spot. I was told part time was 30 hours a week. three weeks ago I took a drug test for a promotion. My pay hasn't changed, nor has my job title. I have been perfoming all function of said promotion and haven't had a raise or change in job title.