Kareoke box not working

I bought a kareoke box on 21 oct at Makro Vaal, i had the box 2 weeks and the microphone did not work and the battery went flat very quickly... i gave it in and waited 2 months to get it back after repairs. Had it 2 weeks again and again the same problems. Now they do not want to give my money back. The person ont the phone calvin said they hardly ever get problems with these boxes... so he is basically saying i am lying... will never ever buy anything with the name polaroid again.