Flexicare not to be trusted

My sister took out an insurance with Flexicare but soon after realized that she got a better option with another company and two days later sent them a text and an email to say she wishes to cancel the insurance that was on the 05 October. We received an email confirming receipt of the email. Low and behold yesterday all of a sudden she gets an sms and email saying that they will start deducting the premium end of this month. I immediately called on her behalf informing them that she does not want the insurance. I was surprised to learn from the operator that they "apparently" did not get the email. I gave the operator the reference number of the confirmed email and was told we would receive a message from the billings department cancelling the debit order. Worse still the certificate issued was dated 28 October two weeks after she had cancelled her request. We are still waiting for the cancellation confirmation email from them.