During software development you have to make choices. How to develop or which api to use. Suppose during development you discover you made the wrong choice. Two weeks of work down the drain or a useless license you bought. Who has to pay for these mistakes, the client who agreed on the proposed method or the development company? I think the latter, what do you think? And even better, how to prevent such situations?
However I know many consultants who simply bill for their time no matter what, even if the path taken leads to complete failure or results in time wasted.
If, on the other hand, you care only about results, you should have asked for a flat-rate bid on completed work by a development company. In that case, "how to develop" or "which api to use" shouldn't matter, since you are no longer making development decisions but simply awaiting delivery of the features you paid for.
You can't have it both ways: either you're hands-off and pay only for results, or you have a collaborative environment in which you call the shots (since you are writing the checks) and are responsible for dead-end paths.
As as side note, I wouldn't get into finger-pointing and bad blood here. If you truly care about your product, move forward with it. You could easily spend more on litigation than the 2 weeks were worth. Better to spend you energies on something productive. If you don't like the way the development company is treating you, amicably part ways.
"either you're hands-off and pay only for results, or you have a collaborative environment in which you call the shots"
Many thanks for both your feedback. Realy helpfull!