You are able to cancel your appointment from the TM2/TM3 Online Booking Portal.
Login to the booking website or register a new account using the Login / Register button. Once registered or logged in click on the My Bookings tab.
This will show you a list of your booked, cancelled and previous appointments. Click the Cancel Appointment button on the appointment you wish to cancel.
You will be asked to confirm your cancellation.
Click on Yes.
The appointment will now show as cancelled within the My Bookings page.