Help with possible inmate scam?

A friend of mine has been a pen pal of someone who is incarcerated. She met this person through her son who was incarcerated with this individual. (We will call him 'Ben'.) Now according to 'Ben', he owns three limousine companies outside of prison and is very wealthy. He has a handful of people who "work on the outside" for his business and has promised to send money to my friend if she does favors for him. (I.e. Letting him keep contacting her via letters, collect calls, sending packages to friends, flowers to women...etc) These favors were supposed to have been 100% reimbursed plus, a paycheck for doing the actual favor itself. Unfortunately ( and not shockingly) 'Ben' has not followed through with any of these. The only thing he has succeeded in doing is having a puppy sent to my friends daughter. No money has ever been reimbursed, the promised truck has still not been delivered (which she put $350 on his books for) and he has not followed through. Strangely enough, somehow (because she did not share any financial information with him) $150 was overdrawn from her bank account this morning and put onto a prison calling card. After calling SECURUS this morning she learned that this transaction was done from an unfamiliar email address and from the internet but she doesn't even own a computer or know how to use one for that matter! We dont know that it is him yet because we cant find any information on this email, but everything is leading to 'Ben.' What can we do? Is this a typical prison scam? Or is it extortion? She needs to do something and have this guy legally handled. please help!