32GB Sandisk Micro SD suddenly stopped being recognized by Galaxy S3 phone

My Sandisk 32 Gb Microsd High Capacity just up and quit on Saturday 7/5. I bought it the day before the Galaxy S5 was released, installed on my brand new phone which has never beed dropped.  I tried all teh suggestions by using a USB reader on my laptop and desktop, using the laptop card reader, trying to read on a tablet, all of which has failed. The tablet refers to it being damaged and Window 8 doesn’t even recognize it. I emailed SanDisk on Saturday and got the auto reply: Thank you for contacting SanDisk Customer Support. You should receive an email response from a SanDisk Customer Support Representative within 2 business days.

Will wait patiently until Wednesday to see if I am contacted.