Woolworths refuses to close my account and give me my payed up letter- they are ***********

its been a whole month trying to get my payed up letter with woolwoths, I payed my account off 2 years ago, requested them to close my account they are just refusing, I need my payed up letter too for my records. I have sent them emails called them several times promising to email my letter and close the account but they have not done that.