I paid it by debit card on their website through one of the payment services they use. I think it was PayUSATax. The letter just has the phone number and a caller ID for me. No specifics about actions I can take. I have called them once before and it was a surprisingly pleasant experience. The stories I had heard made me think it would be like talking to a wall. This just has me kind of panicked because it's a lot of money if I can't convince them I already paid it.
