Double deduction and Urgent Notice message

I called Nedbank 2 weeks ago to inquire about a certain arrangement I thought I could make. I was told they don't offer that.A lady who was helping me over the phone was so impatient and gave me just one option which I refused but she went ahead and made the arrangement without my consent.On the 23 October 2015 an amount of R700 was debited from account.Another amount of R1783.33 was debited again on the 26 October 2015.I called them on the 26 October hoping to understand what\s happening