Do not worry about it. You need to call Sears customer service to let them correct the mistake they made. Tell them you cancelled your card long time ago and your account was fully paid at the time. The later fee was not owed and now you got bothered by their collection department.
You will be fine. They cannot do anything against you in your case. You probable need few phone calls to press them to correct the problems for you.
You will be fine. They cannot do anything against you in your case. You probable need few phone calls to press them to correct the problems for you.