I agree that if they ignore you then that's no good. People do get busy but it's disrespectful to not answer, yes. Do you have to keep nagging them to answer you or do they answer just a bit slowly, with a bit of delay?

If you try to talk to them, be assertive, constructive, avoid drama and use positive emotions rather than negative ones. That's quite general, I know, but if you have a specific message you put together, you can share and get suggestions about it from people here.