POOR SERVICE

I spoke to an agent 2months ago and advised I will be making payments via EFT on a monthly bases as I have no money in my account on the day they debit. Woolworths is debiting my account and creates bank charges on my account, when I called this morning this agent doesnt want to listen to what I am saying, she tells me they cant cancel a debit order. So frustrating because I pay before the 7th monthly via EFT