Thank you all and sorry about the delayed reply, please see draft email.
Dear Revenue Enforcement Delivery Manager,
I am writing to address an unfortunate incident that occurred on

ate>, wherein I unintentionally reused a one-way complimentary travel pass for a journey from <A> to <B>. I sincerely apologize for the inconvenience and disruption my actions may have caused.
I understand the seriousness of my mistake and assure you this was an isolated incident, and it will never be repeated in the future.
Please will you allow this matter to be resolved by way of an out of court settlement to cover the fare as well as any administrative costs incurred by Northern Rail in addressing this matter. Please let me know the amount owed and the payment process, and I will make the payment promptly.
Once again, I apologize for any inconvenience caused and I hope that we can resolve this matter as quickly and smoothly as possible. I am assuring you that I will always ensure that I hold a valid ticket for all future journeys.
Your sincerely,
<Name>