Mode continues to run after the ignition key is removed!

Hello, for several weeks I have had massive problems with my car and now finally with the workshop, which made the repair. After my vehicle had sporadically displayed versatile errors and error message (among other things, the running of the engine after the key was removed) the complete ignition lock was changed in the workshop. After I had picked up the car, the exact same problems occurred again. The car immediately came back to the workshop, which, after apparently thorough testing, found out that a control unit “is confused and has to be changed. I have criticized at the workshop that I want to have offset the costs for the unnecessarily changed ignition lock with the current invoice for the new control unit. The factory’s didt tell me that the ignition lock was broken by the broken control unit, and for this reason was not replaced unnecessarily. Now my question, can it be that a control unit damaged the ignition lock and thus the workshop actually had to renew both? Thank you in advance Desiree