Am I screwed on Obamacare because of my VA status?

Today I just found out that I am enrolled in VA healthcare benefits. Apparently I had been enrolled during my out-procesing when my guard unit returned from Afghanistan.

This is a bit of a of a problem for me because I have worked for a small business for the past three years and enrolled in health insurance through the marketplace. For most of Last year I was receiving a subsidy for my families health insurance (myself, wife, 2 kids). My parents however just received a letter from them them showing that I am registered for the required minimumn, and therefore am not elidible for a subsidy.

The problem is I never knew this and will most likely have to pay back the subsidy I received for all of last year ~$2,000. Does anyone know if there is some way I can convince them that I was unaware of the coverage?

As a follow up question, I no longer am eligible for a subsidy for coverage, should I end the plan I pay for that covers me? I can keep my family on it and it would save me about $150 / month. I am category 8d, will the service I receive be even semi decent?