Unable to use Discovery Miles for in-store purchases

I have been unable to use Discovery Miles to pay for goods in-store for weeks now. I reported the issue 2 weeks ago, and I sent in screenshots to ***. Apart from an automated response, I have heard nothing more from them, except one voice message by an agent who wanted to know what the issue was. I have subsequently called back twice, and each time I get another story.

Today I was told that this was an ongoing issue. If so, why hasn't the Bank contacted their clients to inform them of the issue? Why do I have to follow up? Why do they not respond to e-mails? Why do they not call back their clients experiencing ongoing issues?

I am disgusted at the terrible service (or lack thereof).