I have been lucky in meeting some great clients who treat me like their very own colleague in sharing information and sometimes, even offering guidance because I am so fresh in the industry.
There has unfortunately been more bad PR about media agencies and the other side of the story remains untold. There are clients who are unfair and unprofessional about the working relationship. The condescending tone doesn't foster stronger partnerships because we then feel simply like a tool that they are paying and making use of.
Every business collaboration puts both parties on equal grounds. On the other end of the line is simply another person who is working hard to meet his/her KPI and managing expectations like you are.
It takes two hands to clap but I must say we are especially fortunate when there is also the company history and good track record to help boost our credibility, especially for new blood who are learning the ropes.