Excuse me. I made the assumption that they told you they had no duty to Protect You - individually - because you asked them for protection. And I know here in Virginia unless you're accusing someone of a felony, the victim - which is what it seems you were - can go before a magistrate, court clerk or judge file a complaint against the alleged perp and if they buy your story issue a warrant for the arrest of that alleged perp.
And while you give no indication of when this event occurred, in Virginia one has a year from the date of the event to request a magistrate to issue a warrant.
So if the cops didn't believe you, why didn't you take it upon yourself to get the warrant taken out against this alleged perp who allegedly assaulted you.
And just which of your rights did the local cops violate?