Go to a good independent BMW shop but call them first and tell them you need your battery registered.
Coding cable and software is nice but that is all you need. Maybe 50 bucks.
More than likely you have the wrong CCA too but that isn't as big a deal as BMW makes it out to be.
Coding can adjust the CCA too but BMW only has so many choices and what you had installed is most likely not one of them but close.
Remember it is a battery and the only reason for doing the registering is to help prolong battery life.
However from what I have observed on most BMW forums it has not helped much.
A battery tender helping 500% more than registering your battery...