Settlement partial cascade Navi theft

Hello, just landed in an endless waiting loop at the insurance company… Can anyone tell me how the damage will be compensated for with a Navi theft? The Navi was fixed. The insurance already meant that they only replace the time value. Does this mean that I get a fixed amount replaced and what I do with it is left to me? Or do I have to prove with an invoice from a dealer that I have bought a replacement device? Background: I could reasonably afford a return Smoked navigator from private, but without invoice. Purchase contract would be possible of course. I would have to decide on short notice without knowing what the insurance pays… Thanks for the help, Superrudi