You have the right to complain. They have the right to not ship (as it was a donation, like it or not). You have the right not to trust them any more.

I for one do not trust them even if they compensate the backers. The main damage has already been done: they lied to us. Multiple times. Screw the money, screw the tablet. The real loss is the loss of trust. There is no way I am going to believe that someone who has lied to me 3 times is suddenly going to turn around and become all honest the 4th time. I feel sorry for anyone who does.