Before canceling you expat health insurance policy, please keep in mind that you're legally required to have health insurance when living in Spain. Except in rare cases, living in Spain without health insurance is illegal.
You can cancel your expat health policy easily by:
Logging in to your Feather account (simply enter your email address that you used to sign up for your expat policy and then you will be sent a one time password, which you can use to log in);
Selecting your expat policy in your account; and
Clicking on the cancel button.
If you would like to learn more about expat health insurance or would like to sign up, you can do so here.