Following a surge in customers purchasing Happy Meals in bulk to obtain limited-edition Pokemon trading cards, with some of them aiming to resell them online, McDonald’s Japan has issued a public apology and announced preventive measures.

The company held a promotion in which customers were to have gotten two Pokemon cards with every Happy Set — as Happy Meals are known in Japan — purchased between Saturday and Monday. But due to overwhelming demand — many customers were buying large quantities of the meals — many McDonald’s outlets ran out of the cards and ended the promotion on the first day.

The frenzy also led to significant wastage, as some customers bought the meals solely for the cards and discarded the food that came with them. Photos of such incidents were shared across social media, causing shock and anger online.