Dennis,
You have the right to know the details of the debt they are trying to collect. Unless you are confirmed that you really owe the amount to them, why should you pay? If you get any call from them in future, ask them for debt validation. You can also send your request through certified mail, provided they give you their address.
Collection people cannot abuse you over phone, nor can they use objectionable words. They are not allowed to threat you by any means. If they do these, its violation of fdcpa and you can file complaint against them with FTC, BBB or DA's Office.
Wish to hear more from you.
Bryan