Broken TV Postnet Centurion Negligence

I sent my TV via Postnet from Centurion to Vincent East London. My TV was malfunctioning due to Courier negligence it shows two thick lines. When I call Postnet Centurion they gave me numbers for Aramex to complain. I couriered and paid Postnet not ARAMEX. I am very disturbed and angry because they said they cannot me