Aetna  - Scam and cheating!

My wife has been disabled since 1988. She receives a monthly disability check and is enrolled in Part A only. We opted not to enroll in Part B since she is covered by my health plan at work. We reasoned why pay out the additional monthly cost. My wife and I are both in our 50's. I have had no problems all these years until a few months ago. I noticed Aetna was holding all claims with the reason being additional information was required. After many many calls and emails to Aetna Customer Service (or lack thereof) I found out that they showed my wife was in both Part A & Part B. The representative was told that in no uncertain terms that my wife has never been enrolled in Part B. She then confirmed this with the local SS office. She told me the claims would be resent to processing.

Now the bad news.

All of my claims going back to May 7, 2007 were then re done as if my wife had been enrolled in Part B. So far (it keeps changing ever time I visit their web site) I have gone from about $700 out of my pocket to over $20,000. The new EOB (Explanation of Benefits) now states and I quote 'Your plan reduces covered expenses by Medicare benefits for which you are eligible, whether or not you are actually enrolled in Medicare.' My question is what are my options, is this legal?

I am concerned too, that next they may say my wife was eligible for Part D and they will quit paying for her prescriptions. Which run over $1500 per month.

Any insight is greatly appreciated.