illegal activities

What is the name of your state?PA
I posted a few questions before in regards to my husbands employers being jerks. Unfortunately there is no law against this and although possible to prove constructive discharge it is rather hard to do.
My husband has an interview soon for a good opportunity and it's worth the risk of being fired. I know they can fire him at any time becuase it's an at will employment but he knows of some illegal activities that goes on at the workplace, such as they knowlingly billing customers even after they cancelled service. They only fully cancel them after the customer complains a few times. They also keep certain confidential information they aren't supposed to such as cv2 numbers which enables them to keep billing people. What is the appropriate method of bringing these to light?
thanks

What's a cv2 number?

It is the number on the back of credit cards (usually 3 digits I believe).
Some places ask for that as extra security. They're not supposed to keep this information.

I don't know if storing the Card Verification Value is "illegal", but it is prohibited and could result in fines according to http://www.bbbonline.org/eExport/doc/MerchantGuide_cvv2.pdf