Please see the answer to "What is your cancellation policy for travel insurance?" for full details of under what circumstances policies can be cancelled.
Generally, provided you have not commenced your trip or have made (or intend to make) a claim you can cancel your policy within 14 days of purchase for any reason. You can do this yourself in your account area. You do not need to contact us.
Your login is the email address you used to purchase your policy and the password that was sent to you under a separate email.