When I started rebuilding I had two accounts in collections. One old Spectrum acct with Diversified Consultants I paid in full and it was deleted from my report within 2 days of payment.
The other, a Con Ed account placed with Collection Bureau of Hudson Valley, was paid in full in December and I was told it would be reported as paid in full and then deleted from my report within 30 to 45 business days. I did not get this in writing but I recorded the phone calls. In mid January I called the CA again to verify that the account would be deleted. It was reporting as paid in full and I just wanted to be certain it would be removed. Again, I was told it would be removed by the end of January. Today, the account was still on my report so I called the CA back. I was transferred to a manager who said it is not policy to remove accurate reporting. However, I gave him the date I spoke with his representative and he listened to the recorded call. He said that he would honor what I was told and contact the bureaus today to stop reporting my account. He said it should be updated within 24-48hrs!
I am very happy with how well the conversation with the manager went and I cannot wait to see the last collection removed from my account. Of course I will be calling back by Friday if it is not updated.
Hopefully it goes as promised - removing your last blemish should send your scores up big time 
After speaking with DC and requesting a debt verification letter, I reached out to Spectrum directly. I was able to pay Spectrum the $150 debt and DC stopped reporting the account within days of payment to Spectrum.