During WW II German and Czech banks were forced to buy the German war bonds. What happened with these bonds? Were they ever paid?
In 1953 West Germany entered the London Agreement on German External Debts. Communist countries were not included in the agreement.
Further bilateral agreements and payments were made during the 60s (with some Western countries) and the 90s (with some Eastern countries). There were payments to to the Deutsch-Tschechischen Zukunftsfonds, which pays restitution to Nazi victims and supports reconciliation projects.
Note that during the Euro crisis Greece demanded the repayment of similar debts; the official German position was that they had been settled with the 1953 treaty and subsequent 1990 agreements.