PA28R pilot reported trim malfunctioned during climbout resulting in strong nose-down pitch. Pilot returned to departure airport where maintenance inspection found trim control incorrectly replaced during aircraft annual inspection.

Narrative

I just had my PA28R200 come out of annual at ZZZ. It was run up by the maintenance facility and released back to me. This was the first flight since the annual was completed. I was attempting to fly it back to ZZZ1 where I'm based. Preflight went normal as well as the run-up. I took off Runway XX westbound; and I noticed I was using up more runway than normal. I thought this was due to the hot temperature. When the aircraft went airborne; I immediately began to fight the airplane. Something wasn't correct and I remained calm with my focus on flying the airplane. The aircraft wanted to violently nose over. I attempted to adjust the trim to correct the nose-down action with no success. The trim tab indicated it was in the neutral position and was tested during the run-up. I couldn't understand why the controls were so heavy with a strong nose-down pitch. While still in the upwind; I [requested priority handling] due to the abnormality and not being able to fully control the aircraft. Fishing with the trim to try and fix the nose-down situation; I didn't want to be low and slow since I wasn't able to gain much altitude. I kept the power all the way forward and decided to attempt to land back at ZZZ. The aircraft was making power fine and I was able to get it in some kind of stasis where the nose-down pitch was somewhat controllable. I didn't have time to mess with the trim any longer due to being low and was running out of options. When the [priority] call was made; everyone got out of my way and or wanted to help which I'm very grateful for. I added one notch of flaps and went gear down while on the downwind; keeping the power in. Base to final was faster than normal because I didn't want to get too low and slow. The final approach again was faster than normal due to the continued nose-down attitude. Again the aircraft fought me all the way down to touchdown. Luckily I was able to land the aircraft uneventfully with no damage to the aircraft or myself.I was able to taxi back to the maintenance facility and did my best to explain the situation. The chief mechanic discovered the trim was full forward; and the trim tab indicator (white mark) indicated the trim was in the neutral position. Somehow during the annual when the trim selector tab was removed; it was replaced back in a position where it indicated neutral but in fact was full forward. I believe Piper can do a better job with the design of the trim tab and its neutral indicator. As a pilot; checking the trim should be adjusting it full forward as well as full aft; making sure the neutral position is in fact neutral. Moving forward; I will do this on every aircraft for a proper trim test as part of the checklist.