Upgraded contract, money deducated twice in 1 month, never refund, rude attitude Canal Walk

Hi. I upgraded (renewed) my contract on 12 of October, 2017, in Cellur shop Canal Walk. I paid the balance with my credit card on 12 October, in full R1381.41. Shop assistant, who confirmed my payment, told me that the debit will NOT go on on 25 Oct because I paid with my credit card. He never cancelled anything as debit order went though on 25 Oct. Now they even refuse to give their Head Office ph number and put the phone down (cut the line) - it was done 3 times !!! on 3 November. .