I recently gave my S8 to the Samsung service centre because of a problem with the sim card. They fixed my issue, but after the service, my SD card was locked and my phone couldn't decrypt the data. I hope they upgraded my software and that caused this issue.
I spoke to Samsung customer service centres and they have no solution for it, which is completely unacceptable. You guys own the product and firmware, so why can't you be careful with it? I will need a solution for this and there should be a way to get my data back. It's a 128GB SanDisk full of my kid's photos :(. . Any help on this will be greatly appreciated, guys.