Through somebody’s good offices
Definition 1 of 1
Pro Tip 1/3Connotation of Assistance
The phrase often implies that the person helping holds some influence or authority that was pivotal in assisting. 
She found an apartment through her boss's good offices.
Pro Tip 2/3Formality Level
It is formal and best used in professional or official contexts, rather than casual conversation. 
The treaty was signed through the good offices of the ambassador.
Pro Tip 3/3Not Literal
The phrase is figurative, meaning the person's influence is used, not their physical office space. 
We resolved the dispute through the good offices of a mutual friend.