Sometimes we as people make mistakes. Perhaps you got a few bad marks on your credit report, but you paid them off, yet they are still there causing difficulty. Lets address this.

Contact all 3 credit bureaus immediately about those negative accounts. Tell them that those are the specific accounts that you are disputing and tell them that those accounts are wrong, that they are now paid in full.
In the interest of saving time when dealing with the credit bureau’s send a copy of your license with your letter, also send a copy of your proff of residency, and a social security card copy.

Once this is all settled, your credit score should improve in 6 or so months.