Dispute Captial One mistakes on my credit report

I am writing to ask a question about a letter I sent directly to Capitol One about 2 debts that show on my credit report. (I have attached that letter)
I have only had one credit card with them and not sure which account number it was so I disputed both entries. I think the statute of limitations is up on them, but not completely sure. The letter was mailed certified on March 26, 2007 and it was deliverd on MArch 28. To date I have not heard a word from them, despite the fact I included my address and asked for a response within 30 days. I had also disputed this with Experian and the very next day they said they verified the information and no change would be made, but they have failed to explain how they verified the information or the accuracy of the verification. If Experian verified it so easily then why has Capitol One not responded?
I am not sure what my next step should be. I have been cleaning up my credit for the past few months and the paid items still look like negative entries.
It just seems to me that if you try and make right on the negative it still remains for 7 years as a negative. May as well not pay it and wait for it to expire.
I will be glad to scan a copy of my report for your review so I can get the most accurate advice.

Thank You,
Live Human
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majors@oskie.com / to Live Human / show details / May 17
You should have a name phone number or address to contact the verified account with the origianl creditor. Use those to contact that creditor to get a paid in full or out of date.
Just mail letter again using the same method.
The zero balance does hel even though the account shows late payments. So paying always helps your score in the long run