Honestly, that's just sort of name of the game for this sort of ad provider service. It sounds like you're talking about Tapjoy, which is really one of the best at fairly crediting rewards. I'm glad Nordeus works with them.

Just accept that part of the process is taking screenshots and sending contacts. You'll learn which offers will be straightforward and which require a bit extra, or have a chance of frustration at the end (like "sorry, didn't qualify" surveys...). Make it easy by setting up a standard email to send with the offer name, screenshot added in. Add it to the process by emailing right away if you think an offer won't deliver.