Revolving accounts on credit report

I am working on repairing my credit and pulled up a free credit report from Transunion. Under revolving accounts I have three accounts. The first was sent to collections but I signed on to a payment plan and now that one is paid off since December 2011. Can I have this removed since its been paid off already? Unfortunately, I did not have the collector sign off on paper that they would remove it after the debt was paid. Is it still possible to get it removed and what are the steps or am I just screwed and stuck with it? The second account I have one more month then I'm done paying it off too. And same situation with the second account. I would want it removed also but am not sure if I would have to contact the collections agency or credit bureau or which one first. With the first and second account, they are both listed as derogatory. Will this come off too once I have it removed (if it's even possible)? The third account I didn't even know was still open. I'm pretty sure I cancelled it 4-5 years ago. I called the credit card company and they said they don't have records of my account and with the info I provided, no account pulls up. What are the steps to fixing this issue? This account is listed as open and I've heard it's not good to close out accounts but don't I want to close it out because it doesn't even exist anymore?