I feel I cant trust ShawMax with my bank details anymore

According to Showmax I've created two accounts with them of which I can confirm with them and the other I can't because I did not created a secondary account niw they have billed me twice and can't refund me for the second account of which I did not created they can't give me any direct answers or evidence I feel I have been ****med by showmax *****ing /***** extra money out of my account of which I have proof abd have proof as well of my converstion between me and call centre assitant as well as his name how far can I take it or what can I do