the region code is written physically to the drives firmware chip.
there are several ways to reset the region code count
1)using the manufacturers unlock key, but this will only work for 4 times, so that 20 changes in total - unlikely ull hav access to this
2)reflash with a MODIFIED firmware - u can get hacks that multiregion the drive, don't use the official firmware as it preserves the code settings
3)desolder the cmos chip and replace with new one
but then u might as well buy a new drive
dont bother wiping th os or reinstalling the drive, it wont work