Your information is wrong. MergedMining has never paid that low of a dividend per share... Looks like A) you aren't a shareholder B) you didn't do your homework very well.
Sorry for the 'tone' of this message, but it really bothers me that I am constantly having to take the time to correct information that people post about MergedMining due to their lack of ability to actually perform decent research. Please people, if you are going to attempt to provide the community with information, make sure you actually know what you are doing.
No problem, I see what might have happened. During the migration from 1.0 to 2.0 the history was not moved over, but if my records are correct I was paid 0.1921980 BTC for the 302 shares I had at that time. That is 0.000622 BTC per share I had.
Also,
here you state that 6.22 BTC was paid. With 10,000 shares that is 0.000622 BTC per share.
The previous dividend on 3/19/2012 was for 0.00128976 BTC per share.
How much did you send per share? I can update the information if what I have is incorrect.