What are my options regarding negligence of the NYPD in investigating my claims of harassment and illegal surveillance?

See below case that might help you, but sorry, personally I don't deal with those types of cases: 

TORTS, MUNICIPAL SPECIAL DUTY OF CARE, FAMILY LAW: When does a municipality assume a special duty of care with respect to a plaintiff for purposes of enforcing a Family Court temporary order of protection, subjecting the municipality to liability in negligence for breaching that special duty, and, relatedly, when may the municipality may rely on the governmental function immunity defense?

The Second Department held that the complaint adequately alleged a special duty of care and should not have been dismissed. The court concluded that the Family Court order functioned as a temporary order of protection, that plaintiff sufficiently pleaded direct contact and justifiable reliance on the defendants’ efforts to enforce it, and that the defendants did not conclusively establish governmental function immunity at this stage, given statutory provisions arguably requiring police action in response to violations of such orders. (Boyd v Village of Mamaroneck)