This is the answer BMW south africa gave to the sales person at the car dealer:

"Hello Natalie, the customer most likely only has SA494 (Seat Heating) and the owners manual referes to Active Seat Ventliation (SA453).
If SA453 is not part of the vehicle then the backrest heating will certainly not work. SA453 also forces Perforted Nevda Leather.

Hope that this information is sufficient.

Please do call me if you require further clarification."

I do NOT have active seat ventilation or the perforated leather seats. I do however, have comfort seats which I believe are no longer available.

I do have the seat heater distribution.

Perhaps cars made earlier in the model year had it and later ones don't or perhaps it is different in your country....

I'm in the same boat. I have Comfort seats, not ventilated seats and I have heat distribution control.