I laid a complaint with BMW still no response

I took in my 3 series BMW to Midrand Auto Bavaria in Septermber because there is something eating the battery power of my car. I was told by a guy called Collen that the car has been fixed. Less thana month later on the 15th of October I got the same warning sign on my car that there is something eating the battery power again, I called Midrand Auto Bavaria to book it in and Collen told me to take it to the dealership I bought it from,<br> I called JSN Motors in Bryaston and I booked the car in. They kept my car for 6 days, told me that they had cleared the fault but they could not explain to me what is eating my battery power.The lady I was dealing with called Melanie told me that she cannot guarantee me that it won't happen again.I called BMW SA to complain I was told I will get feedback after 48hours and they still have not responded to my complaint. I've had the car back for 2 days and it's giving me the same warning sign that my battery power is low. My car is still fairly new and it's already giving me problems. I want this problem fixed by BMW SA. They manufactured the car so they need to be able to fix it when it has problems.