I the first part - I would say, all they were guilty of was having rude customer support. They were well within thier rights otherwise.
However, if OP is to be believed, what they have done after finding out this has been posted in the public domain seems inexcusable. Threats & forgery are defnately crossing a lot of lines.
Get an amicable solution and move on.
My 0.02$ is just cut your losses. This is not worth the mental agony you are going through. Value your time. Not every battle must be fought.
