First of all you can claim a refund from the train company who was responsible for the delay. 

Then you can also as for compensation from Interrail/Eurail. Read more here:

https://www.interrail.eu/en/support/delay-compensation

You need to check the conditions for the Eurail pass. There might be different rules for persons living within Europe and outside of Europe. 

DB/bahn will only exchange the old RES for domestic (and as its only optional, noone will really care-also due to the enormous amount of delays and canceled trains at the mo anywhere in DE) to a new one. But the 4,50 is just above the lower limit for pay-out;

HINT; most germans in the know go to a counter-often they give you a voucher you may use for tickets or for buying in the bistro-car.

Refunds-delay compens. is only via the site -after pass has been completely used-just find page-and how much will depend on type of pass-on a continu pass for 1 month or more you will need to collect at least 3 > 1hr delays for a tiny sum. Yes, that is far, far lkess as to what GBers are used to @ home.

My train THA9422 will be cancelled on 09/08. It cause I cannot meet another train that is Eurostar IC5131 dept from Paris to London. I can’t catch up the train on time. So. I need to cancel  both trains and refund. But I don’t why the Eurostar train cannot make refund. The system shows that it is not refundable. Please help urgently. Thanks.

Please get in touch with our customer service team via email on customerservice@interrail.com or customerservice@eurail.com so that we can arrange a refund for you. Please ensure to include your reservation number. Eurostar trains are famously non-refundable but please include your reservation number for the Eurostar too so that we can try regardless.