I'm still looking for an attorney who will file a class action suit against the government for this very reason. As far as I'm concerned, I had a contract with the government which said that if I contributed to my SS account for a given number of years, I could retire with full benefits at age 65. Now that I've been paying into the plan for more than 40 years, they change the rules and I have to keep working to age 67 in order to get full benefits.
If a private insurer pulled a stunt like that they'd wind up in jail. Why should the government get away with it?