[Client name] had [X] weeks to answer a major client's security questionnaire. Their previous provider had told them everything was fine.
[One or two more sentences on the situation, in the client's own words where possible.]
Our audit found [X] accounts belonging to people who had left, default settings across Microsoft 365, and backups that had never been tested.
"It wasn't what we wanted to hear. It was what we needed to hear."
[Client name] submitted its answers on time, with evidence, and passed with no findings. [Add the commercial result: contract won, renewal, premium reduced.]