Auto approve deadline incoming, but participants haven't returned their submission

I have a study that is going to be auto-approved later today however a few participants have not returned their submissions after I requested them. I have sent a ticket to Prolific to ask them to return it. What if I don’t see Prolific returning them, say 4pm today, should I reject the participants first and let Prolific change them to return? Or is there a number that I can ring Prolific to flag this up as an urgent request? Thank you.