Google Maps Platform billing - 75% adjustment approved, $327 remaining marked "final verdict" - escalation exhausted

Had an accidental Places API runover July 24–26 (no budget cap configured, $1,310 total in 48hrs, single incident). Google Billing approved 75% ($982.53) — grateful for that. The remaining $327.52 has been marked “final verdict” by Escalation Manager after two reviews (Case #73959216). All internal billing escalation paths exhausted.

Clean multi-year Google account history (Gemini, Workspace), project permanently deleted, zero repeated usage. The entire incident was a one-time 48-hour window.

Has anyone here successfully resolved a similar situation? Is there any channel beyond the standard billing escalation path?