Ignoring my request for cancellation of vision direct policy

I requested that my policy with vision direct be cancelled this month and such wasn't done. They asked me to send proof of other insurance i have done so. But now they are sending SMS that I will be debited such amount ignoring my request for cancellation. Why do people have to always resort to coming here on hellopeter , whereas such issues could have been resolved in a easy way. It is a bad practice.