FSM marked my account PAID IN FULL but won't give in writing

YES!!! You definitely need this in writing. Keep at them.

You need something in writing so that the company doesn't sell the balance to another company and they will pursue collection even though you were aware of the account been paid. You have to have some proof and file it in your records.

Would they be willing to send this confirmation by e-mail? You would need something in writing so you can protect yourself in case something pops up in the future. I would keep after them.

No I got it in writing. Not sure how that got on there? I just want to know if I should keep writing for a refund and proof of all payments?

So they did give it to you on writing..How long ago was this?

last week