Hi Iwishyoulove
Welcome to the forums.
It seems that the previous company whom you made the payment has not updated your account with the credit bureaus. Write a letter to that company explaining the need to update your file because it is hurting your credit ratings negatively and you are being contacted by some other agency for the same account.
You can also place a dispute with the credit bureau that has reported this account. They will investigate it with your information providers. After your dispute is found to be valid, they will update it and send you a free copy. Usually, it takes 30 days to send you a free copy of your CR. Hopefully, you will get positive results and improve your credit worthiness.