Hi Homos and welcome to the NS Community! 

You will only get a refund for a delay for your journey with NS. So I think you checked in and oud with NS from Zwolle to Maastricht, right? Unfortunately, you will not get a refund from Kampen because that was a trip with Blauwnet.

Welome to the NS Community!

The refund is only for the NS part of the journey. Kampen - Zwolle is Blauwnet and Maastricht - Vaals is not by train (at least not by NS train).

Either way, the refund would be the same because from Zwolle to Maastricht is already more than the maximum of 200 km (€ 29,40).

From Kampen costs 9 cents more (€ 29,49), of which € 4,19 goes to Blauwnet and € 25,30 to NS.

The correct refund would be € 25,30 (or 40% less because of a subscription) but if they paid you € 29,40 (or 40% less) consider yourself lucky.