technical issues and arrogance

on the 1st of june my debit order bounced. i contacted vodacom and requested the debit order to be resubmitted around the 12th...but kept on getting calls from their automated systems that my account is in arrears and i can opt to have my debit order submitted and that if its not paid my service will be suspended....i thought perhaps the call center agent did not complete my re-debit request so i proceeded to opt for debit order resubmission on th 15th (again their pathectic IVR system would not allow me to select any specific dates, and i tried various options and it finally allowed me to enter the 15th) via the IVR system. LO and FLIPPEN behold, they have debited me TWICE !!!! now my bank account is overdrawn and i face additional penalties. I called vodaom and they basically told me its my own fault because instructed them to debit on the 15th. ***!!!! why is it my fault ? why did their system keep on calling me EVEN AFTER I ARRANGED a re-debit on the 12th... so they promised me the supervisor on duty would call me back (this was around 5pm), but as usual, no callback,no care..... BAD SERVICE, BAD SYSTEMS , just plain simple BAD PLANNING...how far does the incompetence go?