Horrid experience with NEDBANK, Green Backs and their AVO App

I recently wanted to make a purchase through AVO which is Nedbank’s an online store and is in in fact endorsed by them. Upon registration on the AVO app, I was asked to link my Green Backs points to the AVO platform/app to be able to make a purchase. The AVO app is then directly linked to your Nedbank Green backs account (on Nedbank Banking App). An amount was displayed on the AVO app and I was prompted to continue to make the transfer of points (or so I thought) between the Nedbank and AVO apps. I proceeded to do so and it was only then that I realized that ALL my Green Backs points were transferred over. A huge part of the confusion here is that there are 3 different 'currencies' that Nedbank chooses to use ie. Green Back Points, AVO Points and an actual South Africa’s currency, Rand. This amounted to just over R12 000. The value of the item I initially wanted to purchase was in the region of R1 499. After I realized what had happened, I immediately contacted Nedbank to get this reversed. To date, they have absolutely refused saying that AVO is not allowing them. This strikes me as strange because as I've already mentioned, AVO is endorsed by Nedbank as can be seen at the bottom left side of the Desktop AVO website. I am in the process of lodging a complaint with the Banking Ombudsman but I can't believe that I have to go to this extent to sort something out that is supposed to have been an internal Nedbank issue. I ALSO can't believe that in the last 24 years of banking with Nedbank, financing my home as well as multiple vehicles, the fact that I also have my son's account (which is also in excess of 15 years old) with them, that they are so willing to lose my business this easily! There's unfortunately no negative star rating which is what I would've have selected. A 1 star is actually too good a rating for the service I've received from them!!!