Not happy with the service

I applies for wifi connection beginning of July ,i havent recieved the service. I spoke to the agent by the name on Elizabeth Ngobeni, she told me a guy buy the name of David used my address now no one is able to remove him because in need the sevice. He used my address without my permission, can someone disconnect him i need the service. Elizabeth is not even responding on my calls and watsapp now.just useless. Can someone help me please.