[Date]
[Name concern]
[Position]
[Address1]
[Address2]

Dear mr/ms [Name concern]:

I am writing to inform you that I would like to request the cancellation of my insurance [policy number]  effective [date].

Please send me the written confirmation within 30 days that the cancellation has been put into effect. Refund the unused portion of my policy premium and stop charging my bank account for payment of monthly premiums.

Thank you for your prompt attention to this matter.

Sincerely,
[Your Name]