My policy ends after age 65, but I'm not retiring until almost 2 years later. Can I challenge this?

I have been disabled on Social Security and on UNUM Insurance from my Bank employer since age 50 and I am about to turn 62. Unum has been fair to me since we agreed on what was 60% of my commission only income and I have no complaints of their service. So based on what I have read, I count my blessings. My question is that they say my policy was written only until age 65 despite 66 and 10 months being my retirement age. This puts me in a terrible position as my income drop will be nearly two years before I expected it and four years before my wife (who stayed mostly at home and raised our four children) can retire at age 67 at 50% of my Social Security. So I am wondering if there has been challenges of this sort before and, if so, what has the outcome been? The two year difference is substancial as a class action and there should be a litigation path to succeed in a claim of this sort. I have a memory of being told by personnel that “disability benefits end at retirement” during our employee meeting but I have no other proof and a very bad memory as my disability is from a loss of memory due to a brain injury. I may not be considered a reliable witness, even though my memory prior to my injury was pretty good. I remember my whole life before twelve years ago. What is your view, is there any case law on the issue or does it just fall into what ever was written in a contract in small print?