On the openness of #IoT or lack thereof

Me, to the developers of a very nice Bluetooth Smart sensor:

I’m considering writing some code that can read the data from your SensorBugs. I don’t want to use your mobile apps or go through your cloud, as the code is supposed to run in close proximity to the sensors on a box I have at home.

Is there any documentation how to do that? I failed to find any.

Response, and I quote in full:

No documentation – they are sold as a closed system.

Needless to say, I will not be buying from this vendor.