Was TOLD cannot refund as money is accepted by machine - Consumer Complaint for Ang Mo Supermarket Pte Ltd

I was at the branch in 639 Punggol Drive and made some purchases. One of the item was a Sunshine bread. I thought it comes with a free Kaya but was told it only comes with the bigger loaf.I was brought to a sign which indeed shown the Kaya is free only with the bigger loaf. I then said I don't want to purchase the loaf then but was told by the cashier. CANNOT.- because money is paid into machine. Sounds ridiculous. I do not want to create a bigger scene because of the current pandemic situation but would really want an answer...is it true? Money paid into machine means no refund if I don't want the bread. That is the exact word by your cashier.