Bought E-ticket but met strike

This is the best way to try. It may take some time though. 

https://www.ns.nl/en/featured/recommended/strike-compensation.html

What compensation am I entitled to?

We have listed your options, our offers and how you can redeem our offers below. Conditions apply, including the Terms & Conditions for the NS Delay Refund Scheme (GTBV). The words 'service' or 'train journey' always refer to an 'NS service' or 'NS train journey'.

• E-ticket or single-use chipkaart (paper ticket)

  You have an e-ticket or single-use chipkaart (paper ticket) that is valid on the day of the strike. We have listed your options, our offers and how you can redeem our offers below.

  • Your journey is delayed by 30-59 minutes
    Partial ticket refund. You can redeem this offer by submitting a Delay Refund request.
  • Your journey is delayed by more than 60 minutes
    • Ticket refund. You can redeem this by  submitting a Delay Refund request.
    • Or a new ticket for future use. Contact NS Customer Service to request a voucher code.
  • You decide not to travel because your journey would be delayed by more than 60 minutes
    • Ticket refund.You can redeem this by  submitting a Delay Refund request.
    • Or a new ticket. Contact NS Customer Service to request a voucher code.
  • You opt for a different, paid means of transport because the strike has made your journey impossible.
    You are entitled to up to €25.00 in compensation for alternative transportation while the strike scheme is in effect. To request this compensation, please contact our digital co-worker Jens, NS's chatbot. Available today from 9.00 to 22.00.