Collection Account on My Experian Credit Report

[number1fan]

I received a letter from a collection agency stating that I owe them $700, I pulled my Experian credit report and noticed that they had this item listed on my report for 6 months prior.

My question is, I thought they had to notify me within 30 days of posting negative information on my report? This same item may have been listed by another agency 2 years ago but was removed, by whom I don't know, it just vanished one day. I sent this new agency a verification letter, and sent a dispute letter to Experian. It appears they both had an address for me in a city that I have never lived.

I filed an online complaint with Experian in which they did not remove the report so I sent them a letter this time stating that I was not informed of this neg posting within 30 days by the CA and that the address and city they have for me I have never lived at. Is there anything else I can do? I am still waiting to hear back from the CA, its been about 2 weeks, I know they have 4.