A bank card should only be used by the person whose account it relates to (or by the attorney if you have POA), so if you were advised to allow other people (carers) to use that card, then that advice is wrong, not to say criminal. Not that this never happens - I, in common with many other people, used to draw out money for my mum when she was incapable of doing it herself and before I got POA, but I had my mum's best interests at heart, as I'm sure most people in this situation have. No way would I have allowed strangers to have access to my mum's card. I don't want to alarm you but the bank may well feel they have no responsibility to sort this out if anyone other than your mum has had access to her card.