Dealing with Mypaydayloan

I'm dealing w/the usual garbage from mypaydayloan.com (oops, did I violate copyright laws?). Up to now, I have been successful settling with my other pdls by using the info found in these forums and my own research. I live in PA and have been in contact with the PA Banking Dept and State Attny General; both confirmed that payday lending is illegal in PA. The places settled w/include: Plain Green (asked for refund, nothing); Moliloans, EZpaydaycash, 500fashcash, and paydaymobility (only response was a nasty phone call). I placed an ACH hold on an upcoming payment to them; I had borrowed from them before, always paid in full on my due date. Then I realized how much "interest" I had already paid them, so I proposed an amount that was principle minus interest for last 3 loans. They sent me all that mumbo-gumbo about Costa Rica laws; they don't do loans, but do advances on checks (funny but the word loan is plastered all over their website; hell, it's in the name of the company); they don't charge interest, but charge flat fees....blah, blah, blah. I have given them 3 offers (I upped the payback am't slightly each time). But, they still won't buge. I did file a complaint with the PA banking Dept and waiting for the form from the Atty General. I told them of my intentions, but don't think they believed me. Since this started, I've gotten a phone call each day at work; all I say is please see the letter I sent, I won't comment on phone, put it in writing, good-bye. The latest response is that they will sent my account to an outside collections agency. Anyone out there have info about this; do they, and if so what agencies? How can someone collect on a debt that can't be validated or illegal?