1. Previous Communication Reference: Include when there have been prior attempts to resolve the issue

2. Legal Rights Reference: Reference to consumer protection laws when escalation might be necessary

3. Alternative Contact Information: Additional contact details if primary contact is unavailable

4. Compensation Request: Include if seeking additional compensation beyond correction of the overcharge

5. Carbon Copy (CC): Include when copying the letter to other relevant parties or authorities

1. Original Bill: Copy of the disputed bill showing the overcharged amount

2. Correct Bill/Price Evidence: Documentation showing the correct price or rate that should have been charged

3. Payment History: Record of previous payments and billing amounts for comparison

4. Communication Records: Copies of any previous correspondence about the issue

5. Service Agreement: Relevant sections of the service agreement showing agreed prices/rates