Capital Mgmt. Serv. ,LVNV Funding LLC letter stating I owed 2600.00 to LVNV funding LLC, never heard of them don't owe Buffalo New York

received a phone call from Capital Management services on my cell phone, saying I owed, SBC 2600.00, then referred to them as HFN, Household, all the way back to 2002, I told them I never heard of such people, and I knew for a fact I did not owe this money, he continued to harass me saying they were going to take me to court, and suggested I did not get irate with the judge, like I was doing with him, pretty much belittling me over the phone, finally I hung up, 2 days latter, i receive a letter telling me I owe this money,
i know for a fact this is a bogus account, i check my credit report all the time, no such thing i on it as of right now, but I am worried that some how these people will find a way to get it on there. I don't know quite what to do except ignore it, or write back.

Tami
mchenry, Illinois
U.S.A.