Disab. Ins. COLA? Cost of Living?

[jonis4]

What is the name of your state (only U.S. law)? WI
I have been diabled & receiving benefits for 12 years now. I have been receiving both SS and private Disability Benefits since. My question is why doesn't Met Life have to give me a cost of living adjustment each year? My ins. book states that i should be receiving COLA's yearly. when i asked them 12 years ago, i was told they don't adjust because SS already does.
Now my eldest daughter is 18 and off to college. Her benefits have stopped and my youngest daughters benefit has increased accordingly through ss. I did inform Met Life about the change in my dependent's ss benefits. The amout of my primary ss benefit and my daughter's benefit, add up to more than my initial Met Life benefit. I am concerned that they will no longer entitle me to any benefit. If that initial benefit would have been adjusted for COLA annually, they wouls still need to pay my out my benefits. Does Met Life owe me back pay or is this all legal.
Any info or advice would be greatly appreciated.
Thankyou!