It was listed in the terms of eligibility on apples site right after they announced it. It wasn't easy to find but if you google iPhone upgrade eligibility it will come up. So to be fair apple did technically inform everyone of how the process works, although not very actively and they should have said it in their email after reserving your phone.
While I am absolutely sure your correct ... Why not tell the customer that up front when you have them in front of you purchasing it. Or at the minimum tell them once they hand you their company credit card. Then as stated insult to injury they took my debit card and tried a 2nd time.
And why not take the customers company card with their name on it or debit card?? Your financing their credit history. If someone has never made 1 late payment on anything ever (cars houses Etc) why would they not pay their $45 a month iPhone bill.