I'd like to add a little more to this - our main frustration isn't necessarily because of these technical difficulties. Communicating implementation details and 3rd party integrations can be challenging, especially if one side of the convo is not super technical. That is totally understandable, and probably inevitable.

The main reason this felt so...sucky for lack of a better term, is that we had multiple discussions about our use case and were told that this would be supported (again, this turns out not to be true? not a huge deal, it happens), and were asked to pay $20,000 upfront of which we got $0 back once realizing the original promises were not true.

As OP pointed out, 20k for a huge company like DS might not seem like much, but for a small start up like us it is. Just from a consumer perspective, this seems like a crappy way to conduct business.