Write a response to a customer complaint.

What they're upset about: {{issue}}
What went wrong on our side: {{actual_cause}}
What I can offer: {{resolution}}
Company voice: {{voice}}

Structure:
- Acknowledge specifically what happened (no template phrasing)
- Take responsibility where appropriate
- Explain (briefly) without making excuses
- State the resolution and any next steps
- One sentence of human warmth

No "we apologize for any inconvenience this may have caused".