to give someone the money that you owe them, especially when you do not want to:
Eventually they paid up, but only after receiving several reminders.
(from Cambridge Advanced Learner's Dictionary)
09.02. - Nokia Asked to Pay Up for Pulling out of Germany
The German state of North Rhine Westphalia is demanding that mobile phone
maker Nokia return millions of euros in public subsidies that were paid to
it to finance a plant.
The DW-WORLD Article