Pilot reported a NMAC on final approach.The pilot has talked with local FSDO and has attempted to talk with the tower manager. The pilot is not satisfied with the responses received as of this report date.

Narrative

I departed from ZZZ1 around XA:00 under an IFR Flight Plan filed by by my instrument rated Co-pilot/partner. My wife was on board and we had an uneventful flight handled by ZZZ Approach; ZZZ1 Approach; and finally ZZZ Center. We were handed off from ZZZ Center to ZZZ Tower 10 miles to the south; after reporting that we had the field in sight; and canceled our IFR flight plan. After contacting ZZZ Tower; the controller informed me that I would be #2 for Runway 10 following another aircraft; and to extend my downwind for right pattern Runway 10 due to other traffic in the pattern.I was Pilot In-Command (PIC) with my partner as Second In-Command (SIC); and we both monitored ZZZ Tower and watched for traffic. I was 200 feet on short final and 1/2 mile from the threshold at 85 knots. As I was scanning the runway environment for landing; Aircraft Y appeared in the right upper windscreen; and crossed above us about 100-200 ft. heading 360 degrees; 90 degrees to our 100 degree runway heading. I commented to my partner and wife about the nearby traffic and how it wasn't appropriate for another airplane to cross our path on final at that close altitude and heading. Conditions were VMC; unlimited visibility; no clouds.Upon landing; I changed to ZZZ Ground; received my taxi instructions to the FBO; and proceeded to the ramp and shut down. I picked up my son; we boarded my aircraft and proceeded to taxi and depart for ZZZ1 at XB:45pm.I contacted the ZZZ Tower Manager; and described the event. The Manager told me he would look into it and contact me. I did not receive a response. Two weeks later; I attempted to contact the manager again. No response has been received to date. Nearly a month later I forwarded my email message to the FSDO as they are responsible for the ZZZ operations. I immediately received a telephone message from an inspector from the FSDO. His voice mail was: 'After talking with the controllers who are aware of the situation and there was no need for a deviation due to the setup of the pattern. The aircraft was above and behind you.' Given that three witnesses in my aircraft clearly saw Aircraft Y flying closely above and in front of our approach through the windscreen; the inspector hasn't undertaken any review of the radar or audio recordings. It is impossible that we clearly saw Aircraft Y from our windscreen so there is no possibility that Aircraft Y 'was behind and above our flight path' according to the 'controllers'.In addition to this incident; I also reported that a online search of the tower results in this phone number: XXX-XXX-XXXX. After repeated attempts to call this number; it is disconnected. I contacted the FBO office and was given XXX-XXX-YYYY. Apparently this is the correct number to contact ATC. When I contacted the administrative assistant; and forwarded my email to Tower Manager; I again requested that the phone number should be updated. The XXX-XXX-XXXX remains disconnected. This is a serious safety issue. In the event of a NORDO or other in flight emergency; a cell phone call may provide assistance to a pilot in distress.