Capfin spam calls

Capfin spam me everyday with phone calls. They always ask to speak to mister Chamane (that is not me) and every time I respond by telling them that I am not the person that they are looking for and that they should remove my number from their database, yet without fail their call center continue to call up to 3 or 4 times a day asking to speak to mister Chamane. I have tried everything. I've tried being nice, I've tried being firm, I've asked to speak to the call center manager, I've dropped the call; I've screamed, shouted and threatened, yet without fail they phone everyday and ask to speak to mister Chamane.

I have now resorted to pretend that my name is Chamane. When they ask for my ID I give a random ID number and then they say it's not right. I continue the ruse and keep them on the line until they get tired and drop the call.

How do I stop being spammed every day? It's becoming tedious now.