Student or Learner
Mr.David wanted to know why he has not been informed of the decision.
Do I have to change tense in this sentence?
but if it doesn't need to change, please explain the reasons.
Thanks in advance
Actually, this sentence is OK, if you consider the time of the action.
Mr. David called the office. The secretary goes into the manager's office. The manager asks, "What did Mr. David want? The secretary says, "Mr.David wanted to know why he has not been informed of the decision."
Meaning: Mr. David requested to know why, all this time, he has not been informed.