The only proof is that they have a no-refund policy. I know in my heart that I was screwed by the merchant and its sad that when the merchant made outrageous claims with no evidence, it doesn't really matter because of the no-refund policy.
As it stands right now, I cannot use their service anymore because its time sensitive in nature which is also the reason I had to go with a competitor. I never received the service and I have to pay the $1000 bill. Of course the merchant claimed that the service was always available that I backed out. Its a long story but I was jerked around and they baited-switched me and after I asked for a refund, they rescinded the bait-switch. Right now the merchant never lost anything either except the time it took them to write the nasty letter to American Express.