The most substantial grievance was that the people in power such as governors or wealthy merchants exploited the farmers who had to suffer because they didn't have as much wealth or political power and if they opposed they would be arrested or even worse. Social problems were running rampant at the time and Shays knew this.
There wasn't because all positions of power who could've helped were corrupt. Courts, merchants, banks, the local government, everyone was corrupt and worked together in a system to exploit the local people for their own personal gain. The strong central federal government did not yet exist as the Articles of Confederation were in place and not the Constitution.
This is called the "Elastic Clause" and it grants the Congress power to pass laws they deem as correct. This is also called the "Necessary and Proper Clause", and it is very controversial among American citizens.