Re-entry permits come in single and multiple re-entry. Single permits cannot be used more than once, multiple re-entry permits let you use it as often as you like. Multiple re-entry permits are only available at the immigration office that issued the extension of stay. The airport booths are open
Sjef van Ballekom going in with your pink ID Card, yellow house book, and Bangkok Bank app doesn't really work in your favor to show you are a genuine tourist
. I've made it a point to maintain a personal relationship with a banker at my bank's HQ and that has helped in a few situations. When you go to pick it up take that person a something small and grab their name card. It may pay off in the future.
Don't bother with BBL at Central World, go to the Silom head office and go to the second floor to the international transfers desk. These are the only people at the bank that can help you.
I had to wait about 30 minutes one time, but unlike David I was sent to the front of the immigration queue so total was about 35 minutes. I'd be cautious and take his advice though, they may send you to the back of the queue after getting your reentry stamped in