Write a Professional Apology Letter

Write a professional apology letter for a business situation.

Situation:
- What went wrong: [DESCRIBE THE ISSUE]
- Who is affected: [CUSTOMER / CLIENT / PARTNER / TEAM MEMBER]
- Our level of responsibility: [FULLY OUR FAULT / PARTIALLY / MISUNDERSTANDING]
- What we have done to fix it: [ACTIONS TAKEN, IF ANY]
- What we are doing to prevent recurrence: [PREVENTATIVE MEASURES]

Requirements:
- Open with a direct, sincere apology — do not bury it
- Acknowledge the impact on the recipient
- Take responsibility without excessive self-flagellation
- Explain what happened briefly (no excuses)
- State what has been done to fix it
- Close with a commitment to do better
- Tone: sincere, professional, not overly formal