BANK REWARDS DOESN'T WORK!!!

Yet again another issue. Got my gym membership cashback today, but it's not the full amount. The app is showing that I am saving 100% on my gym membership fee but the cashback is not reflecting this!!!! Every month different issues with this bank. When logging queries at Discovery it always just gets escalated and you get promised a callback. NEVER HAPPENS. This is the worst bank ever, would not recommend Discovery Bank to anyone!!!!!