My child's dentist sent me a bill from procedures over a year old. Do they have a right to collect?

The last time we visited my daughter's dentist was on June 25th 2013. That day we learned her father (whom we don not speak with yet he has to pay for my daughter's health insurance through a court order) stopped paying for her dental insurance. I was then left with a $130 bill I had to pay that day. I paid it and unfortunately never returned to that dentist since we no longer had coverage. Fast forward to today, over a year later, I receive a bill for $247. I call and they tell me they were going through records and I apparently had an outstanding balance. My questions are: What gives them the right to decide that I have a balance due over a year later when the last time I visited the office my account was up to date? And do they have a right to collect? I no longer have my daughter's insurance card so I can't even call the insurance company and try to dispute the procedure they didn't cover since she is no longer covered.