Telkom Insurance and bad service

Telkom and it's insurance has bad service. I emailed them the beginning of July to cancel my device insurance and I was told it it's canceled though they are going to debit because it's supposed to be 30days notice before it can be cancelled I didn't mind that but now my invoice has been emailed to me but insurance still appears on my invoice though the 30days notice has already been served. Can I get help I don't want that insurance I need it cancelled.