I’m sorry to hear that you have run into this situation. Unfortunately no, you will need the current correct installer code to activate an Alarm.com System Enhancement Module (SEM). This is unique to SEMs due to the way they are set up.
It sounds like from your description that the system was paid for, and the new communicator is what is still being financed. If their concern is the ownership of the SEM, did you suggest they take the SEM back and give you the code? That would let you just add a new SEM and get started.
If they are not agreeable, another option might be to factory reset the panel, though this would require reprogramming everything. See instructions regarding this at the bottom of our DSC SEM setup guide here.
In either case, a replacement SEM and free first month of service can be found here. And this SEM would be yours to do with as you please (even use with another provider if you want)
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