Discovery Insure Cancellation

On June 6, I requested that my policy with Discovery insure be cancelled. According to Discovery, turnaround for the cancellation should take 72 hours. However, come July, the policy hasn't been cancelled, and I get debited. After following up on 2nd July, Discovery claimed that my cancellation is still with retentions. So I reversed the debit order that went through as I can't pay for a service I'm not using and also have to pay my new insurer.

Followed up again on July 4th, and on July 5th received the same feedback that my cancellation is with retentions. And then on 6 July discovery sent me an SMS and email saying that my policy is in arrears and my plan suspended!

Many many 72 hours have passed since my cancellation Discovery! Please rectify this.