Micros SD card no longer readable on Mac

I have a Tenvis monitor that uses a micros SD card.  I have it to watch our 2 dogs when we are gone.   Yesterday on the app I chose format SD card.  This morning I put it in the adapter and inserted in my Mac and got “The disk you inserted was not readable by this computer.”   I followed instruction on this site to format the card.  I got the message "Erase process has failed. Click done to continue.    When I check the camera app there is O mb on the card.  Can I fix this?   Have I ruined the card?