How to cancel Telus home security due to faulty product

The last tech installed a separate wifi box for us just for these cameras and when we changed our house wifi somehow it still disconnected the cameras on us and the Telus internet guy didn’t understand why that even happened and couldn’t troubleshoot anything for us. We still don’t have working cameras. I still want to cancel because this has been nothing but headaches and a waste of money. We have spent hundreds of extra dollars to get technicians out here just because of wifi. No one told me when I signed up that if there was even so much as a password change the whole system will stop working and I’d get charged to fix it. People should be able to change their own wifi passwords.