My guess would be that when the IAA tries to charge the fee, your bank 'automatics' automatically say NO to the transation.
Some days later someone in the bank reviews, or goes through, the transations that were denied. Upon checking your case about a denied transation by some entity called IAA trying to charge whatever amount, he/she goes to check who the hell is the IAA, and comes to the conclusion that, Oops, that's a trustworthy entity and he/she 'manually' overrides the automatics and allows the transation to be completed.
Naturally your bank does NOT want you to know this. They don't want you to go to the bank bitching ... I had my licence application delayed some days because of this BS.
Welcome to the world of automatics.