Not informed of a double debit

I called after the 4th of September to change my debit order date to the 9th of the month as I changed jobs and now get paid later. The call centre agent changed my debit order date as requested and made no mention of a double debit in October. I remember specifically asking her "So R228 will be deducted from account on 9 October?" and she said Yes. This morning R228 was deducted from my account twice by Liberty Life. I now have to incur charges to reverse one of these direct debits. If you are actually bothered to call me to sort this out, you will need to call me before 10:00 in the morning as I am unable to take calls after 10:00.