Bad car service by BMW Fountains Pretoria

I've had a very bad service at the Pretoria BMW fountains. I took my car in to be checked in mid 2017 as it had a low coolant signal. I was told that the car coolant just needed to be "added" or "refilled" and that the technicians did that so the car should now be fine. The sign then re appeared two weeks later, still last year but towards the end of 2017 and they told me that the service guys/technicians did not see anything wrong with the coolant system, the signal was not there when they looked at the car. Now in January, 24, 2018 the signal comes up and I take the car in to the bmw dealer, they then call me as usual to tell me that the car was done and that I will be picked up to collect it per usual, when I get there I was then told again that the service guys/technicians did not see the signal when they looked at the car so nothing could be done on the car, I told the lady at Reception (Lebohang) there that I was not happy about this as I found it hard to believe that the signal that was there for a week would just go away on its own. A couple of days later I called BMW fountains and spoke to a lady called Sharon, and she said it was not uncommon for my car (BMW x1, 2015, 76km) to have coolant problems every two weeks. It is now 14 February 2018 and the coolant/water signal is again lighting up. This is very unsatisfactory for a reputable and expensive brand like BMW. Are they stalling to replace or fix this until I run out of my motor plan. Not happy with this dealership.