sorry for the data loss with the card ... but ...
I have to admit, you did something (or better omited it)
you shouldn't do.
You used a storagedevice without giving it a one-time full-write-test
as a start. I do that with all my harddrives and with all my flashdevices
(SSD, USB-Sticks, SD-cards and CF-cards) ... I use a testprogram that
fills the device entirely with data and re-reads all files from the device.
Since the data is not just nul-bytes, but a nonrepetitive sequence of
bytes, it cannot be tricket into beliving the malicious device-size of a
fake-device. Only if this one-time full-write and full-read has been
running successfully I use this device for any other purpose. (Upon
failure, I would return the device to the vendor (if bought new)).
Unfortunately, cards that are not even recognised on a device-level
can hardly be recovered by simple SW ... I keep my fingers crossed, but
I don't see you getting your images back from this card ... sorry to say so.
PS: Just to make sure you get my point ... executing a test as I usually do
will not generally save me from such card errors ... but such errors will be
less likely ... at least, if the error is not related to a malhandling of the
card (or just bad luck aka static electricity) in the moment the card failed.
For errors due to a failure that is already dormant in a device at the time
you get it from store, the procedure helps ... since most technical devices
follow the "bathtub-curve" regarding the likeliness of a failure ...
a certain amount of errors at the beginning of the lifetime ... a long
period with only few errors and a rising amount of errors at end of life.