AETNA IS A THIEF!!

My situation: I had an accident in April 2015 which resulted in 5 major surgeries and 3 weeks of coma and 2.5 months in rehab. I am now in a wheelchair and lost my feet. As a result of all the surgeries, I am in dialysis 3 days a week to kidney damage. I was on STD through another company – no issues there. Then I went on LTD through AETNA 9/15/2015 I received my benefit payments of 60% of my salary Sept/Oct/Nov/Dec/Jan. Then I received a phone call from AETNA stating that I was eligible for SSDI and they were cutting my benefits as a result. They reduced my payments by the estimated amount that SSDI is supposedly going to pay me. However, according to ssdi, I am not eligible to apply for SSDI as I plan on going back to work 7/1/16. AETNA has been paying me the reduced amount since February. Today 3/31/16 I received a phone from them stating that I own them $11,000 in over-payments due to their error. I don’t know how they are going to get blood from a rock as I was living on it to pay bills., had to declare it as income and paid taxes on it. I am made to feel like a criminal for using a benefit I worked for from my company. I don’t feel that I should have to suffer due to their agent’s neglance/error. They admit it was their error…but they will come back at me for the monies. I don’t know how to handle this situation.