As I understand, they are not retaining your data, but will pull the plug on a service you now depend and are not offering migration options, am I correct? This is certainly an awful business practice it could be illegal, but there is a problem.
At the time they failed to communicate the pricing so you started using their service, judging it would be free. If they started to charge, you could just pay or move to another provider, but the very model of their tool makes it impossible for you to truly "migrate" to another provider since the links are widespread, this isn't exactly their fault (nor yours).
If they are charging you 995$ just because they know you are out of options you might have a case, but that's so time/money consuming I would advise you to just do your best to migrate the widespread links.
http://web.archive.org/web/20130401021533/https://bitly.com/
It had the new brand in use, and it had a "You Business?" link to Enterprise site:
http://web.archive.org/web/20130404123817/http://www.enterpr...
The enterprise site advices you to contact them for pricing.