Hi {customer_name},

We regret to inform you that your appointment request with {business_name} has been rejected. Here are the details:

Date: {booking_date}
Time: {booking_time_start}
Service: {service_name}
Staff: {staff_name}

Please feel free to contact us if you have any questions or need further assistance.

We apologize for any inconvenience this may have caused.

Best regards,
{business_name}