What did the will say? Did you sign a waiver of notice OR a waive of bequest? You need a probate lawyer to read that documents you executed to find out if you were cheated or not.
That document seems to be a document that is used to open the estate, not make distributions. However, the comment above is correct and you need to show what you signed to a probate lawyer. If there is an estate still open in the probate court, you may have some additional rights. However, you should act quickly since there is a time limit for claims, etc.