Incorrect debit order

Yesterday morning at about 9 or 10 o'clock I received a call from an agent from Nedbank collections department informing me about my account and confirming a payment received on the 15th of Dec, through our conversation I specifically asked the agent since I've been debited already will my next debit be end of January, and with a clear response the agent answered yes, now I acknowledge my account is in arrears and the agent asked me do I want to do an arrangement and I specifically said no as I have a lot of debts to cover this month. Then 2 hours later I happen to be debited again the same amount which I did not authorize. I called in the contact center and spoke to Luther who advised me to email my bank statement and since the funds are not reflecting as yet I must call in the next day (today). I emailed the statement and called in as I was told to do so and was never told that id never get my refund. I called in today and I'm told Luther is on leave so I spoke to Nthabiseng who blatently told me I will not get my refund cause I'm in areas. my frustration and argument on this matter is that I specifically verified on the first call and now I'm told something else. I'm very angry.