Incorrect/Double Billing-Don't solve problem

Double Billing and overcharged by Multichoice two months in a row! Have even mailed enquiries says will reply within 24hrs still nothing. My debit order for the last two months goes off at a high amount and the following week another one goes off also different amount. Customer care makes you hold on for ever & cannot explain what is happening the worse is I must go to the bank get a statement and fax it to them and they will investigate. What about my money - sorry will deduct overcharge off next months account - which was never done. They make you holds on forever and refuse to phone you back. My call my time and money again - second time was 18min on my cellphone, Yesterday put me on hold for 12minutes music playing in my ears whilst she is checking told her I am on prepaid phone after 44minutes it cut off bang end of story - no courtesy call back. had to go to the bank waited 30 min in queue to cancel second debit order again. So problem still not solved - will have t start again from scratch to phone again and yes they do not refund the overcharged monies. Who gives them the right to double bill me twice in a row and I must have the inconvenience to try & solve the problem