Subject: Request for Additional Documentation

Dear [Recipient's Name],

Thank you for the attachment. We have received the prescription and medical conditions; however, we kindly request an itemized invoice that includes the treatment date, amount, and treatment details to proceed with your claim.

Additionally, given the high amount involved, we would appreciate it if you could provide an official proof of payment at your earliest convenience.

Thank you for your attention to this matter. We look forward to your prompt response.

Best regards,

[Your Name]
[Your Position]
[Your Company]
[Your Contact Information]