Fractional Captain reported an NMAC with a helicopter while on final approach.

Narrative

Nominal flight until XA:00. A traffic alert was issued to us by the control tower while on the ILS Z Runway XX. A helicopter; Aircraft Y; was to pass behind us. Shortly after; a TA advisory was given by our TCAS system. Momentarily; it went away. The helicopter changed course and another TA was given; immediately followed by a RA with 'climb now' instructions. Our lowest reported altitude was 825 ft before taking action (XA:03). Aircraft Y's altitude at this time was 600ft. Only 225ft of vertical separation. We followed RA guidance until clear of conflict and ultimately flew the published missed approach to an uneventful 2nd approach and landing on Runway XX.I called clearance delivery after landing and requested the helicopter's tail number specifically to list in this report. They initially seemed very willing to comply. Then; I was provided with the Tower supervisor's phone number and told to ask him. When I called; he refused to provide the tail number. I said that I found this behavior odd and that I can locate the tail number using flight aware and/or liveATC.Suggestions: ZZZ Tower needs to severely limit helicopter traffic in its approach corridors. This is the SECOND time this year that I have had a helicopter fly directly at my aircraft while approaching ZZZ resulting in a RA. ZZZ Tower should be transparent and provide the tail number for the purpose of these reports. Refusal to provide the helicopter's tail number induces distrust.