“Question for oral surgeon about proper bone graft code?”

So I had an appointment to get a dental implant on my (left incisor) tooth. That tooth never came in, so when i got braces, my orthodontist actually created the space needed for an implant via braces. So, when i went for the implant surgery and the surgeon cut open my gums, he noticed that there wasn't enough bone for the implant, so he did a bone graft only and closed me up, and told me to come back a few weeks for check up. The office used dental code D7950 for the surgery. The issue is that my insurance doesn't cover that code. They only cover D7953. I called the dental office to double check the code. The receptionist said she'll talk to the doctor about it and call me back. Since my insurance doesn't cover it, iIll have to pay $1500 out of pocket. I really don't have that money. I need to hear from other surgeons to see if they used the correct code.