Date: 201706
Local time of day: 1801-2400
Location: ZZZ.TRACON, US
Light: Dusk
Aircraft: B737 Undifferentiated or Other Model
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Climb
Airspace: Class B ZZZ
ATC / advisory: TRACON ZZZ
Reporter organization: Air Carrier
Reporter function: Pilot Flying; Captain
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Communication Breakdown
Second reporter function: Pilot Not Flying; First Officer
Anomaly: ATC Issue All Types; Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural Clearance
Detector: Person Flight Crew
When detected: Routine Inspection
Result: General None Reported / Taken
Contributing factors: Human Factors
Primary problem: Human Factors

Narrative: I was the Captain. In our Pre-Departure Clearance (PDC); we were assigned the Departure from Runway; with a clearance to 'climb via SID.' Per procedure; the departure and the climb via clearance were briefed thoroughly. The climb via has a top altitude of FL230; and per Company procedures we initially set 12;000' in the MCP window. After takeoff; Tower switched us to Departure. When we checked in; we incorrectly stated 'climbing to one-two thousand.' First Officer (FO) and I quickly discussed that we needed to indicate that we were climbing via. At this point; the Controller asked if we were indeed climbing via; and this was clearly confirmed with the Controller. After flap retraction; VNAV was engaged and FL230 was set into the MCP. My recollection is that the aircraft continued to climb per the clearance without any further issues. Other than the clarification on the climb via verbiage; the Controller never gave any indication that anything was amiss.Two days later; I received a phone call from (name); Company ATC Specialist. He indicated that ATC was claiming that we had leveled off at 12;000'; contrary to our 'climb via' clearance. The First Officer and I had no recollection of such a level off. I found this whole issue very puzzling. Although I was quite sure that we had continued our climb; if we had made an altitude error; why had we not been queried by ATC? It then occurred to me that [our flight track] shows lateral and vertical tracks (in great detail) for each IFR flight; and can be pulled up online. I looked up our flight; and sure enough; we climbed as cleared at more than 2000 fpm.  I called the ATC facility. Confronted with the fact that I had empirical evidence supporting our recollection of the continuous climb; (name) indicated to me that the story then changed substantially. ATC was now saying that the Controller was concerned that we 'might' level off. If this was the case; the safe thing for the Controller to do would have been to confirm the clearance again with us. However; this did not occur. This left me wondering if ATC would have continued with certificate action based on an absence of factual research. Fortunately; because of modern technology; I have proof contrary to their claims. I am very thankful that (name) brought this to our attention and that our airline is supporting us. To the best of my memory and understanding; we did not operate the aircraft contrary to the clearance. If this is not found to be the case; please advise me so that I can learn from this event.If my understanding of this situation is correct; it would certainly appear that ATC is acting in a very predatory; Ready-Fire-Aim manner as far as dealing out enforcement actions on our Pilots. I have learned that our flight is just one of many on this departure being pressed by the FAA. I find this manner dealing with issues to be very damaging to the good working relationship that our Pilot group has historically had with ATC. These actions do nothing to promote Safety; and actually create a barrier to Pilot-Controller cooperation. Furthermore; I feel that the individual who is threatening our certificates; when apparently we operated per the clearance; should be held accountable for this attack on our clean records and careers. Additionally; if problems with altitude compliance are commonplace on the Departure; then perhaps the procedure should be changed or studied by Human Factors Analysts. Barring that; perhaps a Read before Fly or bulletin on the Weather Package should be added to draw Pilot attention to this issue. Pilots do not make mistakes intentionally and are quite skilled; as we know. Multiple transgressions indicate a systemic problem with either the departure; our VNAV procedures; or both.


Second narrative: [Report narrative contained no additional information.]


Synopsis: A Boeing 737 crew reported that during climb; they checked in with departure and mistakenly stated they were climbing to one-two thousand feet.