Hidden 5.1 Track In A 2.0 Track?

[Matrix789]

Hello everybody, first of all I apologize for my bad english..
I have a soccer game in HD 1080i, divided in 3 parts: first half, second half and over time, each one composed by the video track and two audio tracks, one 2.0 and one 5.1 (in theory). The file extension in .ts.
The 2.0 track is about 65MB while the 5.1 one is about 130MB.
I demuxed the 3 parts of the game with eac3to because I wanted to create 3 .mkv files with only the video track and the 5.1 audio track. I didn't have any problem with the second half while for the over time part eac3to recognized two 2.0 audio tracks instead of one 2.0 and one 5.1. I opened the bigger one (130MB) with audacity and I saw that there were 6 channels, not 2, so I exported the track in a new file and then I muxed it with the video track, creating the .mkv file and solving the problem.

But the first half is a different story: I am in the same situation of the over time part, with two 2.0 audio tracks, one of 65MB and one of 130MB; the problem this time is that audacity can't recognize the 6 channels of the bigger track, but just 2.
So I wanted to ask you if there is a way to force audacity to recognize correctly all the 6 channels. I've uploaded the track on dropbox, you can find it at this address: https://www.dropbox.com/s/13cxn5asnhbdvxq/First%20Half%20-%203%20-%20AC3%2C%202.0%20channels%2C%20192kbps%2C%2048kHz%20%28MAYBE%20FALSE%202.0%29.ac3

Thank you.