What should I do? No pay for 3 weeks?

I work in a Mexican restaurant as a hostess. Normally we turn in our hour logs at the end of two weeks and get paid a day later. Well, that's how it was. Every once in a while we would get paid a few days later. But it's been three and a half weeks and I have not been paid. The owner told my manager that "he doesn't know what happened to the checks." And that "the UPS didn't bring them." Sketchy, huh? I explained to the manager that I'm going broke and I have bills to pay and he said he could give me some cash for now. Do you think I'm being lied to or something is up? It's a restaurant chain and my friend who works at the restaurant in the next town over hasnt been paid either. A lot of the employees are illegal immigrants and the restaurant has hired an underaged worker before. The girl in my position before me was only 13 or 14. I don't know what to do.