TELUS Online Security - Link to Cancel Plan does not work. Please advise

Signed up for TELUS Online Security a while back due to a promotion. Don't use it all and don't need it. I want to cancel my plan. 

Tried used the link they have to cancel their plan (https://www.telus.com/my-telus/online-security/cancel?intcmp=tcom_my-telus_online-security_link_cancel-your-plan&step=feedback), but I get the following when I try to submit the form. 

if anyone could please help with this, it would be much appreciated. Thank you.