debit order date ignored, threats to block my numb

I have called telkom since month 1 of receiving an sms stating a debit order will go off on a date that i did not authorize, my preferred date was the 15th of every month, this is what my contract states - i have called telkom asking to change the date as i have no funds in my account on the 31st of the month, i was told it would take a month to change the debit order date, now again today i have been told there is nothing they can do if the debit order bounces they will block my number and not pay the bank charges , even though i have called at-lease 30 times telling them that i cant pay on that date - why did i get the option to choose a date if they just go on their own decision of debit order dates, i have now been sitting on hold to talk to a supervisor or manager or director to sort this out and pull all my phones calls complaining about the **** service, i have been posted from pillar to post as a fat joke in the Customer service de[department and have been on hold for almost a hour - worse service ever, DO NOT EVER GET AN ACCOUNT WITH THIS PEOPLE THEY SUCK- worse service and capturing of new accounts, Thanks for nothing Tshego Kgafela and telkom and their directors!!!!!!