What would be the most effective way to communicate our request to Netstrata, and what kind of documentation would be helpful?
Netstrata probably won’t listen anyway, because it’s in their business model to do what best suits them, in the belief that what’s best for them is best for their clients. In any case, you may already have signed away your rights to run your scheme under a full delegation clause in their standard contracts. You can legally resume control but they might not give it up without a fight.