very " simple '' situation. XXXX XXXX refused to change mailing address, kept sending it to old address, in spite of notification of COA by mail, telephone & online. So then, since they could not get the statement to me, I closed acct. that took weeks, instead of a few minutes.. the " late '' charges are because they would not get the billing statement to the current/correct mailing address. 
I think the problem lies not in billing /accounting, but in customer service procedures. We still shop there, as they are handy. The problem is not with local stores, but headquarters.