Customer Service and incorrect Billing

I ordered a product offered for free with just a R70 postage fee payable. After the transaction was processed..... a payment of R1431 was collected. I cancelled the order the day after ordering upon finding out the bank could not help me . They confirmed thr csncellation but today they email me saying the product has been posted today. No mention of ghe refund I requested when cancelling the ordêr. Please assist if you can.