Greenbacks appear to just be an imaginary benefit

I recently paid up my credit card and Garage card. At the time I had R1280.00 in greenbacks that I had earned. The person that I was dealing with said that in order to get the money, I should not close the Credit and garage card accounts until I had app**** for and received a new shop card which I declined to do as I was paying interest on the two accounts. The consequence of that was that I forfeited the greenbacks amount. I earned those points through using their card which was my agreement with them. Had I been due interest on the accounts would I have had to forfeit that in order to pay up my account? I believe this to be a greedy and ************ practise to lock you in to their credit cards. Shame on you Nedbank