Highly disappointed with customer service from Discovery Card

I have been trying to use my Discovery points that I have accumulated over the years since March 2018. The transactions never go through once you enter the OTP. I logged several calls to try and resolve this issue but no one can assist me and resolve this. They have now just ignored it and say they cannot find the issue. I have no issues using FNB ebucks but with Discovery there is always an issue and no one seems to want to assist in trying to resolve this. I continuously pay my monthly fees for no reason as I cannot even claim the points that I have accumulated. Seriously thinking of cancelling this card. The service has been highly disappointing from a company that I really expect more from.