I had a similar experience with StumbleUpon. My account was suspended because I'd supposedly breached their terms of service. Now, I had shared a whole bunch of stuff that wasn't mine, and some that was, and if you looked at their TOS and squinted you could maybe see that perhaps they meant to say "Don't share your own stuff" (except everybody else seemed to, often a lot more aggressively than me). I appealed the decision and have never heard back – and that was several years ago. Because of the suspension I can't log back in to do anything at all, even change my settings.

Needless to say, I gave up on StumbleUpon (which had never been that useful, actually).