South Korean Diablo III players who were affected by Error 37 are being offered a full refund by Blizzard.
A post on the South Korean Battle.net forum states that players under level 40 can apply for the refund between June 25 and July 3. Error 37 occurred as a result of high server loads shortly after the game’s launch, preventing players from logging in and forcing Blizzard to take the game’s servers offline several times for fixes.
An investigation was launched by South Korea’s Fair Trade Commission after a large number of complaints were lodged against Blizzard. The refund is likely a result of this investigation.