Need Payday Loan Advice in Vermont

I took out 4 internet payday loans about a year ago from CLK Management (Ameriloan, USFast Cash, United Cash Loans, and 500Fast Cash).  I'd used these services in the past and had always paid my loans in full, though it was always a struggle as many of you probably already know.  But I've had enough.  Times are tough and just paying the mortgage and holding down a job is challenging.  I've paid these people many times over at ridiculous interest rates.  I closed my checking account and began to do some research.  I found that internet loans are illegal in Vermont and that CLK claims that an Indian tribe grants these loans so they are not subject to the laws of the US.  I am receiving threatening calls.  I know they cannot put me in jail and that they do not report to the traditional credit agencies.  I know they use fear and intimidation and that working out reasonable settlements with them is next to impossible.  I am contemplating just ignoring them.  Can they do anything to me?  What is the track record of CLK in suing people in other states?  Anyone have any Vermont-specific info?  I wrote to the banking commisioner who only confirmed that internet PDLs are illegal in our state.  No further advice was offered.  Not sure what to do at this point.  Thanks in advance for any advice.