I made a purchase some time ago and the store opened a credit account for me that I did not realize with an old address. It is now months later and I just found out that the original $170 charge is now $418, is in collections and has lowered my credit score by over 200 points. They had an old address so I never received a bill. Is there anything I can do to fix my credit score.

Pay the bill with an agreement that they will report the debt paid in full to the agencies

How would they have known your old address? If it was their error show it to them and demand they drop the excessive finance charge. Either way you do have to pay the bill. I am very confused if they had the wrong address how did the collection agency track you down?

I tracked them down since I had a refi to do and became aware of the charge when they pulled my credit report.