When Andreas left the foundation, I requested a refund of my 0.3 BTC donation for lifetime membership. They denied my request.
Allowing refunds would be a great place to start building good will. Maybe if I like the new direction you take the foundation I'll donate again, but holding my donation hostage in an entity that has changed is not cool.
I don't think many/any foundation (or similar entity that accepts donations) is ever going to be willing to give refunds in the way that you request. When a foundation receives a donation they will plan their budget accordingly however if they were to honor requests to refund donations then they would have no way to make a budget.
What you are asking is also essentially that they buy people's trust