Since it appears that you have remaining qualified higher education expenses that exceed the amount of the room and board refund, you do not need to recontribute the housing refund.
Specifically, $28,500 - $20,300 = $8,200 in remaining tuition that was not covered by the 529 plan distribution. Since this exceeds the $2,350 refund, you do not need to recontribute it to the 529 plan.