In the PH I found a lot of SD cards are defective they break after a few days of use, MyPhone and Cherry Mobile cell phones are good at destroying SD cards also... Best to check and see if your cell phone will recognise a different SD card and also make sure your laptop can just to remove the possibility that the problem is with the device rather than the card...
Sometimes if you blow in the slot of your laptop where the SD card inserts into it will read, also try a different adapter the TDK one's seem to be about the best another trick is to quickly insert and eject it a few times... If your lucky it will read and you might be able to copy your data over but mostly you will not be able to but at least if the laptop can see it then in most cases it will format and work again... If none of the above works then it's defective SD card...
Seven times out of ten though by trying all of that I can normally get them to function again and I tell the owner not to allow people to borrow the SD card again and plug it into their virus ridden dodgy cell phones...