Consumer Harassment

This company has been harassing me for years now! It started with phone calls - the company is looking for a Mrs E De Lange... The more I tell them they have the WRONG details - the more they continue to message me all sorts of nonsense, in their search for Mrs E De Lange. I tried to use their Whatsapp line - no reply. I tried calling the offices - no answer. I tried emailing them - no reply. I am beginning to suspect there is some sort of **** going on here as you CAN NOT get hold of these people! I am pretty sure I can sue them for a consumer harassment complaint. It's been YEARS and I'm getting tired of this!