BTER seems to have indicated that they plan on finding a solution to your issue. They’ve acted ethically in all my dealings with them and I haven’t seen any other complaints, so I don’t think it would be fair to tarnish their name.
The withdrawal limit you find suspicious is to prevent mass thefts such as the one that occurred with NXT. 1M NSR is approximately 0.1% of the total supply - not exactly a prohibitive limit.
Also worth noting is that the first warning to withdraw NSR from exchanges happened about a week prior to the dividend: First Dividend, Action Required: Withdraw NSR From Exchanges!
I hope that BTER works with you to get your rightful dividend. However, it should also serve as a reminder to anyone reading this that you shouldn’t keep more NSR on an exchange than you plan on selling. When NSR are held on an exchange they don’t mint, don’t vote, and don’t secure the network. All are contrary to actions we should be taking as responsible shareholders.