Otoh if there is an actual dispute (MS disagrees that they owe you money) then you need to walk away. Nobody is going to sue MS for $7k.
it's royaltees from xblig (xna on xbox360). they admitted to not paying me in email, but don't know where the money went.
I actually emailed msft legal about it aprox a year ago, which got traction for a couple months before their activity died off again.
so yes, as you say the general plan I'll probably go with is to retain a lawyer to send threatening emails. that'll cost in the area of $350. Just tried my best to resolve this without that drama.