How would they know it was you at the turnstile, were they checking every season ticket untill they found the right number!
Anyway to be fair to him though, I never check that my direct debits have come off my account, just know that there is enough to cover them and let them take care of themselfs. If they were being paid without problem in the past I wouldn't expect there to be any problem in the future. I certaintly wouldn't be checking every month to see if ?10 or so had come off for a ticket, just expect it to have.
On the occasions where I havent had enough to cover my phone bill then I'm alerted to it pretty quickly by the company.