nedbank no help

I have made a payment to Nedbank Salt river branch ( branch code BR0021) - ( contact number *** branch manager Eric Gum) of the amount of R 444.20 to Crhistian Barnard memorial hospital account number *** (Dr G Visser - Durbanville 103710) within the first 3 months of 2015 - (jan-feb -or march) - now months later I have received a final demand for payment from a debt collector - -after spending an hour in the Nedbank salt river branch I was told by Mrs Ntshikila that she has checked from the month of Decemebr 2014 - up until Feb 2015 and no cash deposit was found to have been made - then I asked if she would check March 2015 and 30 minutes later was told once again their records didn't reflect this payment to have been made -once asked how many amounts of R444.20 could have been made to that account number she became rude and said I should remember the exact date I made this payment and that nothing was paid in that amount on behalf of a jake Sherman - alas to say they were rude and very unhelpful not to mention wasting over an hour and a half of my time and further frustrating me over something that I feel should be so easy to find or at least try to be helpful .