I don't think that there would be a mileage difference to refund in this case. This would, I believe, require cancelling the 1st award and then requesting a business award - with the new award chart , the business award is more expensive than the old 1st award

If you can get a refund of the 12.5k points difference, then if you want to change to 1st later it would definitely cost the 110k points for the award

If you still have managed to maintain the 1st award, then at least you can rebook into 1st later for no charge

Has the ticket actually been reissued yet? if it has, check the award balance and make sure that ticketing department has not reissued an award