LEWIS FAILING TO CLOSE ACCOUNT AND PROVIDE A PAID-UP LETTER

My Lewis account has been paid up, but they still show that I have an account with them on my Credit History. I'm also struggling to get a paid-up letter which I have been requesting over and over on email and telephonically. I've tried to call their customer service but no assistance has been provided. I don't know why they have not sent me this letter. Why is it taking so long for Lewis to just send a simple paid-up letter and close this account?