Brand Manager needs Ego Massage?

I joined this company month back, boss told me to follow up with the brand manager for creatives. While I have always been quite polite and respectful on my emails, I tend to be casual on chats. Last week while following up for creatives, she seemed a bit irritated saying you can't ask so many creatives on a single day (which were late anyways) and told me she will coordinate with my boss directly

Now, today my boss tells me she is complaining of you being disrespectful and bossy while following up, since she is a senior you shouldn't be like this with her. What on earth such people get from such begging driven Ego Massages? Can't they be just human beings? I am also doing my Job, right?

Later in the day I had a meeting scheduled with her, she didn't join - No courtesy to reply on chat whether she is joining - Call went unanswered - No email saying meeting to be rescheduled. Trust me today was the 3rd time I had to schedule the same damn meeting with her, since she rescheduled twice last week.

People don't want to co-operate in corporate life? I have had 5+ Years of experience and have definitely seen similar behaviour in more people but this has been the peaK