Charter Communications officials believe a software error during routine maintenance caused the company to delete the contents of 14,000 customer e-mail accounts. There is no way to retrieve the messages, photos and other attachments that were erased from inboxes and archive folders across the country on Monday, said Anita Lamont, a spokeswoman for the suburban St. Louis-based company. "We really are sincerely sorry for having had this happen and do apologize to all those folks who were affected by the error," Lamont said Thursday when the company announced the gaff.