Houston methodist billing issues

My doctor prescribed a u/s for one leg due to pain and swelling. I Also got some other diagnostic tests done. Each time I asked verbally to the staff scheduling the tests how much it would cost, they checked and said zero. I have a high deductible plan. Then they also sent me good faith estimates of 0 dollars which I signed. They always had my correct insurance information on file. When the doctor recommended another diagnostic test and yet another good faith estimate of zero landed in my app. I got a little concerned and called my insurance , turns out it was not zero and it would have been 4k usd if I had taken it. Now I have been hit with a 3k usd bill with the tests that have been already done. The u/s would have cost 150 usd at a location not in the hospital. What can I do? I cannot afford to pay that money. Also, I would not necessarily qualify for financial assistance. Had I known it would cost so much I would have shopped around and gone for cost effective choices. More than anything I am angry that the hospital would dupe patients already sick and worried about their health. My local clinic has a better system of charging correct costs for services. I checked my insurance eob, they have paid part of the costs but still the total is more than 3k usd. Anyone has any ideas how I approach this? Thanks in advance.