Problem with the electrician - what would you do?

Again at the beginning, are cables lying everywhere and are they neatly laid and labeled and are all KNX components present?

Are the actuators wired in the control cabinet? Do you perhaps have a picture of how the drama looks?

I actually already said,
the cables have been laid up to the distributor, but the actuators are missing here... the cables are also labeled, whether it is understandable, I do not know.

Yes, sometimes a picture is worth more ;) Unfortunately, the complete actuation is really missing there... then I would bite the bullet and consult a lawyer/expert to find out what can still be done, if it's still financially feasible. Building the cabinet completely and parameterizing everything is still "a bit" of work. Before that, a comparison with the planning documents is needed to see what is already different there.

Are at least the buttons, presence detectors, and sensors available?

Are at least the buttons, presence detectors, and sensors available?

No, nothing available ...

So you need:

[*]an electrician to lay the bus and network cables
[*]the actuators + an electrician to install and connect them
[*]push buttons, PM installation (this might possibly be done by yourself)
[*]complete parameterization of the components

Have you already obtained a quote from a third party? If not, I would do that first.
You can also read up yourself and compile the list of components. However, this requires some background knowledge and time.

So you need:

[*]Electrician to install the bus and network cables
[*]the actuators + an electrician to install and connect them
[*]install push buttons, PM (possibly doable as DIY)
[*]complete parameterization of the components

Have you already obtained an offer from a third party? If not, I would do that first.
You can also read up yourself and compile the list of components. However, that requires some background knowledge and time.

I know a master electrician, he would continue it, but wants me to finalize it with the old electrician...

For me, it is only important whether the old electrician billed correctly.