Instalment increased without any notification, refund is difficult to get back

In November I noticed that Wesbank increased my instalment by +-R800 and when I called to find out why the sudden increase without any notification I was told that Wesbank has decided to add a comprehensive cover and that I should send them an email and request a refund. I have sent through multiple emails and all I seem to get is an automated response requesting proof of my existing insurance cover. This is really frustrating coz they are deducting money from my account and when you email or call them you get sent from pillar to post furthermore you're not even getting any help from an actual consultant. I WANT MY REFUND AND I WANT MY DEBIT ORDER TO GO BACK TO THE INITIAL AMOUNT I PAID AFTER PAYING MY DEPOSIT, I WANT THIS SORTED IMMEDIATELY!!!!