Xtra saver valid for one transaction per day now

I recently shopped at Checkers Virginia. I had to do two transactions. On the second transaction my Xtra saver was declined. The manager informed me only one transaction per customer per day with Xtra saver. There was R400 discount involved on the second transaction. Another customer borrowed me a card, just to save the situation. It was a nightmare, delaying the queue just to pay. Rude awakening to realize a business don't encourage you to do more than one transaction! Don't waste your time to go back to Checkers on the same day if you have multiple transactions and discount is involved. I reported it to head office. They don't seem to care about my concern!