You are correct. In such a context, never can be thought of the same as did not or didn't. We use it when we wish to intensify the emotional quality of the statement. Never is frequently paired with even when we wish to intensify the statement a lot.
You example communicates an emotional feeling kind of like this:
You did not comb your hair, and this failure disappoints me.
But notice that never continues to function as an adverb. Unlike "did not," it does not change the form of the verb that follows: the verb must still be conjugated in the ordinary fashion. The following pair illustrates the difference:
He did not comb his hair. [comb is a bare infinitive following "did"]
He never combed his hair. [combed is a finite verb with the past tense marker "ed."]
The following is wrong:
*He never comb his hair.
Obviously, never can be used in the ordinary sense of at no time. The distinction will usually be clear from context:
Friend: Have you ever been to the park?
Me: No, I never have. [At no time in my entire life have I been to the park.]
Friend: You're old enough. Did you ever see the Beatles in concert?
Me: No, I never did. [At no time in my entire life did I ever see the Beatles, and I never will.]
Police officer: A crime was committed at the park yesterday. Were you there?
Me: At the park? No. I never even left the house. [At no time yesterday did I leave the house.]
Mom: Did you speak to your father yesterday?
Me: Nope. I never even texted him. [At no time yesterday did I text him.]