Student Loan Co-signer go to Creditors Interchange

I co-signed a private student loan for my son he let it go on default, Creditors Interchange got the account contact me with my credit report in their hand tread me to sue me if I don't pay 17,000 in next two weeks. I ask if we can do a payment plan they said they are not allow to do this, they told me to do a home equitity line, cash out all my credit cards, and take a loan from my 401k to settle with them. I'm willing to work a payment plan, can they sue me if I don't pay the 17,000?