Dear …
At times, some of our clients have had to cancel our __ (type of service) __ on specific dates, for one reason or another, and we do understand that this happens occasionally. We are, however, requesting that, in the event you have to cancel your __ (type of service) __ service on any particular date, you please provide us with no less than 24 hours notice. Otherwise, we are unable to book another appointment in your place and thereby, we end up losing revenue.
We have found that this has been occurring quite regularly of late and because of this situation, __(name of company)__ will now be charging a service charge in the amount of __($amount)__ to those clients that do not provide us with at least 24 hours notice of cancellation. It is with regret that we have had to implement this new company policy, but unfortunately, we have been left with no choice. We thank you for understanding our position with this matter. It is our privilege to continue as your __ (type of service) __ provider. You are a valued customer and we appreciate your business.
Sincerely,