a. Adopt, maintain or enforce any regulation, practice or measurement which shall be unjust, unreasonable, unduly preferential, arbitrarily or unjustly discriminatory or otherwise in violation of law;b. Provide or maintain any service that is unsafe, improper or inadequate, or withhold or refuse any service which reasonably can be demanded or furnished;c. Refuse to furnish or supply service to or for any building or premises by reason of a bill remaining unpaid by a previous occupant, providing the person applying for service shall not be in arrears to such company for service previously furnished to or for such building or premises or furnished to or for any other building or premises;d. Make or give, directly or indirectly, any undue preference or advantage to any person, locality or particular description of traffic, or subject any particular person, locality or particular description of traffic to any prejudice or disadvantage.