Collection Problem Help.

I was contacted by a collection guy he said Iowed money. He wanted to work out a deal I told him I could not pay anthing. Maybe later if I could, he made an agreement. I did not sign any and did not say I would in fact pay. I said if I was able witch i was not.He called me today, 5 months later. We got into it over my address I did not want to give it to him he had my email and phone number that was all he needed. He got mad. I called back and asked when was the last activity on the account he siad 3-1-2007. I told him I wanted a letter. He got mad said I was up to something and he was going to turn it over to his lawyers. What can I do to protect my self. I don't have money to pay if He got really mad when I told him it was over 5 years and that there is laws to protect me. Iam trying to figure it out. Help me