Mkv Repair Tool

Meteorite.exe  : http://meteorite.sourceforge.net/

Download, Run, Drag the damaged file in, thats it.

Or Try : Mkvmerge : http://www.fosshub.com/MKVToolNix.html

http://lozaelec.blogspot.com.au/2010/09/remove-audio-language-from-mkv.html