We are going to be sticklers here. Merely hearing what we said is not enough. Neither is nodding. You must have the other person verbally acknowledge what you said and, preferably, ask them if they understand or if it makes sense. Get them on the hook.

Body language can play a key role here. The simple fact as to whether or not they are giving you their undivided attention is a great clue. Look them in the eyes. If they seem like they are in any way downplaying an interaction that you deem to be important by merely bringing up a conflict of yours and asking them to resolve it, then this is a great opportunity to communicate what's at stake.

And, what is at stake, from a very basic standpoint, is the question as to whether or not they value you. Because that is exactly what is going on. Presuming you have presented a valid complaint, they are now deciding at a fundamental level, if they are going to consider your request. Small or big, you should obtain that secondary message. Is your complaint not only heard, but is it respected as well.

Here are the typical ways people don't do that. Something we call the five D's.
1. Depart
They leave your presence.
2. Distract
They change the subject.
3. Derogate
They attack you in return, trying to justify what they did.
4. Dismiss
They say it's not a problem or otherwise try to explain why it's okay.
5. Deny
They say they didn't do it.

Regardless of their response, hold your ground and do not give in. You are worth it.