Useless Municipality

So this is a long story but what a useless Municipality... I have sent them info on 2 fines where someone is driving with my numberplate showing its not my car and I went to the traffic department in Cape Town to remove the number plat from my name but no luck they still say I have to pay the fine even if I have evidence I am about 200km away from where the fine happened. Does anyone know what you can do if someone is driving with a number plate that is not on your name anymore but you still get the fines?