Legal question Employment related

My last job shut down right after July 4th so I was putting in applications pretty much everywhere and finally found a new job close to home at a major manufacturer. The position is for a freight handler for a logistics company, mostly driving a forklift. When I went for the interview I was given an offer for $18/hour and started on the following Monday. 

I just got my first pay stub and they didn't pay me what they quoted me in the job offer. Instead they paid me a lump sum for the position that works out to $16.81 per hour. And then the 1/2 hour of overtime they paid at a rate of $8.30/ hour. 

Not paying what the offer said is one thing, it is a shyster way to do business, certainly unethical but maybe not illegal.  But paying less than 1/2 the hourly rate for overtime is absolutely illegal on both the state and Federal levels. I'm kind of pissed about that and would really like to jam it up their asses but need to line up a new job before I go nuclear with it.

So what say the group? Any way you see this as being something I shouldn't go talk to an attorney about?

Find a new job. Talk to an attorney.

That's pretty odd, especially paying you less for OT than your regular wages. Have you discussed it with whoever is in charge? It almost sounds like a computer program glitch.
Edit to add:
I wonder if it only appears the $8.30 was the overtime rate, as in they figured 40.5 hours at normal rate and then added the 1/2 part?

You definitely need to bring it up.
I despise HR, but they do exist for a reason. And if negatives come from involving HR, then it's a suit for the court to handle. Unless it is small enough company that they don't have a HR.

Go to HR and explain it all. Give them one chance to fix it. If they do not fix the issue make sure you have documentation of your original agreement and what they are paying you and proceed with filing a complaint. It’s always tricky as they will just fire you at the first sign of pushback.