Ok, this 150 days of payout is quite ... well... not reasonable and probably varies as for instance the company that already offers this kind of billing (online, stores, gas stations) in my country, pays you your money 20 days after the 1st pay period ended.

but regarding the billing itself alone I was more thinking of sending an SMS to a certain number, and that SMS would cost let's say $ 2 for one day access. After your SMS has been sent, you receive a reply with your one day password with which you then enter the site.

"and no doubt a lot of people who call will claim they didn't, and someone used their phone."

well this could apply also to Credit cards, 1800 billings, hotlines etc. There are always going to be people claiming that someone used their this and that