If the card friend is not really spending money and can't provide formal invoice vouchers, it is recommended to actively communicate with the bank customer service. If necessary, they can only say rigidly: "Now is a cashless society, who will ask the merchants for invoices?" I've never seen any merchant offer invoices voluntarily. Even if they do, who will carefully keep the invoice? In addition, when I applied for the card, I didn't see your bank reminding me to keep the invoice after consumption, and I didn't see any regulations.
If there is a transaction restricted by Ping An, please refer to the above statement for cardholders who provide proof of consumption invoice. In a word, if you encounter the problem of providing coupons, you must organize your language, pay attention to your wording, and be reasonable and well-founded, so that you can hope to lift it.