Hello Meehyun,
Welcome to the community!
Firstly, you should note these forums are community-driven and not intended as a venue for customer services. We do not have access to customers' accounts. Unfortunately, as far as I am aware, cancellations can only be done by calling them:
You may cancel any or all of your Services and any corresponding Agreement at any time by calling us...
~taken from Terms of Service; section 2e
That said, if you would like to go over your options, you would need to contact customer service. I understand you are currently outside of Canada. They do provide a number to call From Abroad. Calling that number from overseas would not incur roaming charges when called from your Fido SIM (see here). Alternatively, customers should also be able to call that number collect from a landline. I also understand you mentioned you would prefer communication via email. Unfortunately, they do not offer customer service through email. In addition, they also appear to have removed their customer service via social media options. Though, even if those venues were still available, you would still have likely needed to call customer service to cancel services.
Hope this helps 😀
Cheers
