It is not possible to edit or delete a loyalty card once it has been created.
Because it works like a real punch card, when a user gets a punch card with a particular offer and begins to validate some points on it, it can’t be changed (meaning that it would be too easy to attract customers with a big offer and then to change it for a lower one while they already have some points validated on it).
But it’s possible to create a new card with a new offer. All the customers who have already validated points on the old card, will keep using this card until it is completely validated, and then they will get the new card. The customers who haven’t validated points yet on the old card, will get the new one instead.