Billing Error

I have a personal loan with nedbank that I took out it 2014 paid until I was retrenched December 2015 the insurance paid the 12 months while I was unemployed and I was told to take over in January even though I was still unemployed because my insurance cover only paid the 12 months.

Nevertheless I paid the installment in January and Feb debit order was paid on the second week of March after which I had found employment and requested a change of debit date from 31st to the 25th.

The debits have been going well until after 25 June I get a call that I'm in areas apparently I reverserd payment I advised the consultant that my bank doesn't reverse anything above R 200 and as far as I know my payments are up to date, the last person I spoke to assuared me that the payments are fine, However I still get multiple calls after the 25 evert month since June telling about the so called errears. To top it all I don't even get statements so I'm flying blindly.

Can somebody please send me proof that a Debit order was submitted after the change of debit date and was not provided for and why was I not made aware that the is a payment missing, I'm only told months later even though I hold a different view.