You have to present your Cumulus card when buying stamp card products. It may take some time after your purchase before the stamp appears in your Migros App. Please also check the collection conditions for the relevant stamp card, because minimum purchases may be required.
If you have paused a stamp card or it has already expired, these stamps can no longer be displayed nor can they be added to the card retroactively. If you have any other questions, please contact the Cumulus Infoline (0848 850 848).