Plus the billing lady probably has no idea about your actual treatment plan. It may be that she thinks once a c/s always a c/s and bills for that service. Or was told to do that by the office manager.
I did inquire w my dr billing dept what happens if I have a c/s vs vag delivery (I was quoted a vag delivery global fee). They told me it was more (like $500) but not to worry about it until it happened.
If the $1000 is your global deductible, just give them a little bit of money at each visit. Do what you can, I'm sure your not the first patient who couldnt pay all at once. My guess is as long as your paying something, she'll stop hassling you. I know it makes me feel like a loser to tell some one that I don't have the money. But the billing dept's job is to get money from people.