I've had two 32GB SanDisk MicroSD cards go bad recently. One I was able to temporarily revive using the kind advice offered in this thread: Recover Data from Card that cannot be read
When I insert the other into a reader, it registers as 30.6MB (that's MB, not GB).
I've tried all sorts of software and other techniques to revive this card and retrieve the important data off of it (including FindAndMount and TestDisk). Nothing has worked.
So I'm thinking of returning the card for a refund.
But first, I would like to make it unreadable by someone more skilled than myself. Is there any way to do this, given that I cannot even format the card or get it to be recognized as more than 30.6MB?
I am looking for a method that does not entail the kind of obvious physical destruction that would jeopardize obtaining a refund from the retailer. If Costco (where the card was purchased) accepts physically destroyed cards for return, then physical destruction is acceptable (but please have knowledge that they do).
Given two failures, I don't really want to send the card to SanDisk for replacement, because I no longer trust the reliability of their products.