Contract cancelled - 3 months later Im still payin

I have always liked telkom, until recently. Im based in Nelpruit, my 2 year data contract was ending begining December and I decided I wont renew it but will take a WIFI account ,on the 10 December 2015 I walked into Riverside mall nelspruit and filled in a cancellation form, I was told it would take 21 days and the last debit order will go off month end of December... December the debit order went off.....no problem there... until to my suprise end of Jan and Feb amount were going off still...... I dont use they data or tab but R503 are being taken. Month end Jan when it happened i called in and a call was logged and i was promised a refund...Feb again spoke to someone and another call was logged .i promised again a refund.Its March now and Im sure I have 4 calls logged, i went into telkom shop and my line is still active and no one has contacted me to cancel it and they cant help me but log another call. Im definely sure another debit order will go off again this month ... what do i need to do before telkom will close that line.<br> <br> They very quick to open new contracts and upgrades but take more than 3 month to cancel. I WANT MY REFUND!!!