Who Owns the Debt?

I have been unemployed for about a year, and have been unable to continue payments on my credit cards. About a month ago my daughter was able to repay a long-standing loan to me, and I contacted the Collection Agency for the largest debt and made an offer of 40% which was accepted almost too quickly. During the course of the conversation, I mentioned that I understood that this company had purchased the debt from the credit card company, which the agent steadfastly denied. This flies in the face of everything I have always heard about debt collection. Was he lying to me?