Deducting double payments for there own mistake

Multichoice DSTV had not debited their monthly subscription for September 2015, due to an upgrade of their own system...I must know except that they are going to take a double debit for October 2015, which is an amount of R1600 now which I think is unexpectable with out even a phone call to inform us...we are pressured by them to use their debit facilities and now we must pay for their negligence....I am irate because I can't even get a hold of the accounts department and waste hundreds of rands of airtime waiting for them to answer....