Each licensee shall maintain a home office licensed under this chapter as the licensee’s principal location for collection activities. Each licensee must maintain a listed telephone number and must be open to the public during normal business hours on each business day, provided, however, that the director may in his discretion approve a request for opening during hours other than normal business hours or a portion of a business day. A business day within the meaning of this section does not include Saturdays, Sundays, or legal holidays.