I can only offer my own experience of a similar claim. Within the email confirming they would pay was a secure link to an online form to enter my bank details etc. Once I submitted that the payment was in my account a week later. So at the risk of stating the obvious, it's worth rechecking their message to make sure you have provided everything (I'm sure you have by the way)

I can't speak for the multiple passengers issue. Perhaps you need to make separate claims for each person?