If I had any determination, I'd use this recent snub to ensure that it's the last fucktard that gets away with it.
It occurs to me to send him bogus exterminator notices for bedbug treatments with deadlines that must be kept. Or send flyers to his neighbors that he has them and he's refusing access to treat for them. Most diabolical of all would be to actually get them and chauffer them into the apartment under his door.
Gifts? Hmpf. A bottle of skunky beer and a packet of rat poison bait. Drink up and have a snack - you rat!