Testdisk and photorec, use them, they even saved my data from bricked Chinese usb flash drive, so it'll save yours unless you wrote dd if /dev/zero of /*/microsd. Also here's the tip, don't attempt to rebuild partition firstly, first step try to copy all files from microsd to another device with these programs and after that try other ways, edit: I've seen from your other comments that your data already was overwritten, my condolences