Elektron Musical Instruments

> now imagine someone would take your non-crashing MD away and just not
> return it to you. he would tell you he´ll return it to you and time
> after time, you would find out that he obviously couldn´t care
> less.

That's the point. I don't think that Elektron "couldn't care less".
They are surely working on the problem (which affects many users) and 
obviously want to solve it.
If the problem is a defective component, then they could be waiting to 
receive a new batch of fully functional ones... then they will test the 
new MD to check if the problem is still there.
Your MD will come back, fully functional, as mine is; but it obviously 
takes some time.

Anyway, I can understand your disappointment; but, if you want the BEST 
drum machine, you only can wait. I don't think that Elektron will steal 
your money :-)
If you prefer, try asking them a refund, then you could buy a new MD 
when they will be available.
I don't think you'll need a lawyer at all.