Before you mark as duplicate: This is (most likely) not an issue of too small partition, or wrong file system.

Background

Friend’s kid tried to format his microSD card, did something wrong with settings and caused the card to show only ~2MB of capacity. It is almost brand new SanDisk card, which once did have its full capacity (128 GB).

I asked the people to open disk management and diskpart and both have shown only a single partition with MBR, formatted to FAT and having something around 2MB of size. We managed to delete it with diskpart, but then diskpart had shown that the whole card has only 2MB of empty space (so one can only create a 2MB partition).

Question 1: How on Earth that kid managed to shrink the whole SD card using only formatting tool?

Question 2: Is there a way to recover the card, so that one can again use its full capacity? I may use Linux or Mac tools if needed (once I get hold of that card)