So let's see here, the government says that the retirement age is 65 when you start working (and contributing) then gets to unilaterally change the deal? Hmmm.
Not only can the government change the deal, they can in fact take the whole entire deal away. Absolutely nothing in the deal is guaranteed in any way, shape, or form.
Nobody should kid themselves into thinking that Social Security is any kind of true pension program. It's an intergenerational welfare program paid for by current workers' taxes and it always has been from day one. The first recipients paid in nothing into the system.