Sweetie, there are a LOT of questions here.
First, you need to ask them why they haven't contacted you once in the last 6 years.
Are they sure this is the same person? Was it someone whith the sameor similar name?
What proof do they have that you owe this debt? They need to have SOMETHING that proves you owe them a debt.
Also, was there money due when your father cancelled the service, and it never got paid?
Also, if your father controlled the service because you were a minor at the time, you need to tell them that. They can't harass you for a debt your father made when you were a minor.
Also, ask your father about this. He might have some records that would help.
One problem you have is that no lawyer will take this, at least none of the ones I knew in New Orleans would, over this amount of money. You will have to contact a credit counseling service to help if you don't get anywhere with the above. Be VERY careful who you contact. Some are just scams. Call the BBB or your bank and get a referral.

Good luck sweetie.

WW

__________________
"I wondered, am I a lesbian, am I straight, or bisexual? Then I realized that I am just a slut.
So where's MY parade?"

---Margaret Cho