My Ultra 64gb card seems to have died.

Bought tthe Sandisk Ultra 64 GB card for a trip I’m now on. in brand new Gopro Hero3 and after two days failed completely. GoPro can’t even read the disc when inserted (says NO SD). I will return card for replacement or refund when back from vacation). Am flabbergasted that so many problems with this product have already been filed. What is SanDisk’s response?

Unfortunately this product is “ultra” inferior.