Newbie - confused about ways to speed-up video

[WoRkZ]

Hey there guys!

I hope this is the best place to post this. I assume most users on here know exactly how to do what I am trying to... but me, I don't have a clue! So I thought I'd post here so as not to get laughed at too much...

I have these MKV files that have a really annoying problem: The original encoder seems to have messed-up. The video is 23.98fps... and the ausio is clearly too slow. The pitch is too low. The audio is probably from a 25fps source and was somehow muxed with the 23.98fps video by elongating it using a method that also lowered the pitch. Now, since I also know that this specific program was originally broadcast in 50p, I'd like to find a way to simply speed-up the whole file to 25fps AND gain the corresponding pitch elevation at the same time.

Is this possible using a simple method? I understand NOTHING about scripts and that kind of stuff... and I am not very good at muxing (only basic knowledge of MKVmerge). Is this a desperate cause or is there already a tool out there that will make this possible? I am talking about a GUI-based application here... I am no programmer.

Any help would be appreciated since I've been scouring the web and installing crappy applications for the lest 3 hours or so...

Thanks in advance!!!