James' frustration comes after back-to-back Lakers losses were decided by questionable calls in the final seconds.
In Thursday's double-overtime defeat to the Dallas Mavericks, the NBA's Last Two Minute Report revealed seven incorrect calls in the final two minutes plus the overtime periods, including what should have been a foul on James' attempted game-winner at the end of the first overtime.
However, the Last Two Minute Report against the 76ers ruled that the referees got the decision correct, and after a fan on Twitter called it a "huge scandal", James retweeted it and added his own thoughts.
He wrote: "And all year they keep telling me to my face on the court, "I didn’t see it" or "It wasn’t a foul". It’s not making sense to me seriously! Frustrating as hell man! Anyways keep going squad!"
James made a similar complaint in November, referencing a lack of free throw attempts, but he has since seen that figure rise quickly.
Having never averaged fewer than 5.7 free throw attempts per game during any of his 20 seasons, James was awarded just 5.3 attempts per game in October, and 4.5 attempts per game in November. It is the same story for Westbrook, who is averaging a career-low 4.2 attempts from the line.
James was back up to 5.9 attempts per game in December, and has been back to his best since the new year began, averaging 9.0 attempts – a number he has not reached for a full season since 2009-2010 during his first stint with the Cleveland Cavaliers.