multichoice poor debit order systems

i took out a price lock plan from dstv, and it was set up for debit order. the 1st pro rate debit order went off and everything was delivered and installed. a year later i saw a suspicious debit order of R 16 000 from multi choice. i reversed the debit order because it had no idea where it came from and never gave authorization for such an amount. i then called multi choice to inquire and i was told that they were not receiving my debit orders, i asked why was i not notified sooner because since the 1st pro rata payment went through i was under the impression all was in order , all i was told is that there system didn't pick up my account number, so it only picked up my account number when the amount reached R 16 000? i spoke to a Theodora Gxowa very nice lady who managed to calm the situation down. since i didn't want a bad credit record for something that is not my fault i agreed to a payment plan to clear this mess, Theodora said the accounts department would call. i then received a call from a Jackson who was very rude on the line, i was in a meeting and asked to be called back. im since waiting for the call.