Faulty brakes

We bought our Chev Sonic in February 2013 and all went well until the brakes gave us problems not even a year after buying the car. They replaced the brakes and said it was a manufacturing problem. So the problem did not stop their, after a while we had other problems, like the car cut out and I nearly drove through a gate on two occasions so we took the car back on which they informed us we needed to change the brake pads AGAIN! So in 'n nut shell we are going for our third set of brake pads in less than 3 years and the car only has 47 000km on?!?! The after sale manager says it is NORMAL wear and tear. The car is not even 3 years old yet and still under warrantee. To make things even worst when I booked in the car Yesterday they gave me a loan car that was EMPTY!! I had to fill up the car in order to get to work, I am not asking they give me a car with a tank full of petrol but a drop will help. So basically we only get on average about 20 000 or less kilos out of a set of brake pads although the car does not travel in heavy traffic. Even the technician says it is NOT NORMAL.<br> <br> I am really regretting the day we bought this car as it getting very expensive driving it