@OP If you’re talking about the OBD cloned key issue where the the thieves take advantage of the alarm blackspot and use a key cloner to hack the OBD, that’s been fixed for at least two years on cars coming out of the factory so you must be really unlucky, do you know the build date of your car?
Anyway the fix is a free one, just call your BMW dealer and ask for the latest CAS security update, they will book it in.
Anyway be thankful the crims took the car the way they did – I once was mugged for my M5 keys, it wasn’t much fun.