insurance wouldn't cover it, now what?

My dental insurance will not pay for my oral surgery because of the waiting period. I understand that now due to being now charged for the medical expenses that the insurance will not cover. When I went to my oral surgeon, we had request a treatment plan of the whole procedure. They inform and interpret in Spanish to my mother that the insurance did cover it at the time. They give us a rough estimate of what I and my mother was going to pay, along with the insurance cut. We were fine with it and sign the paper to process with our part of payment. "I understand that I am responsible for any amount that are not paid by the insurance company, and it is further understood that the amount above are only the best estimate of insurance reimbursements available a this time." As I was told, at that time and not in 6 months. We were misinformed, and if otherwise told that those were the estimate in 6 month after our dental insurance waiting period, we would have waited. But like the print say, "at the time", we assumed it would cover it. We are fairly new to dental insurance, and were confuse how all this worked. What do you advise I should do?