I've issue with my sd card please help

I've got a tablet from byjus(an edtech) they sent me their device locked with scale fusion but somehow i managed to make it normal . It has a 128gb sd card in which some files are stored. I can't delete the file or make changes to it I've even tried to format it with the help of cmd and it didn't even worked .does anyone knows how can I use it and delete all files .which will help me to get a lot of space.THANKS