I Had Root Canal In The Lower Right Front Tooth.

I had root canal in the lower right front tooth. I was told before my appointment that they would except my discount ins. plan codes 3310 would be excepted. After i was in the dental chair i was told it would cost 700.00. I asked why so much she explained that their would be more charges 3910 and 3999 along with 3310
I was going to walk out. She lowered it to 650.00 and they started the work. I came home and investigated. the codes. She told me that code 3999 was a Meniscus Root canal irrigation. I checked with another dental office and she said that code was for a pre post for a post in the tooth. Please healp