If something like this ever happens again make sure that you make your objections known before the deal goes down, have them register your objection and reason during the shareholder meeting (you won't be able to block the deal from going through) and make it known that if you ever feel that you have been disadvantaged by the deal that you will sue for compensation (and follow through on that if push comes to shove).
As a minority shareholder you have rights, but you will have to stand up for them and push the proper levers at the right time.
Consult a lawyer in your local jurisdiction for the exact detail around the procedure and your options.