Cafin harassment calls

One star is one star too much for Capfin. I am being harassed by Capfin receiving between 15 - 20 calls a day. I have never opened an account with them, dealt with them in any way, but they have my cellphone number which I blocked but they use alternative numbers all day long. I have lodged a complaint with Capfin to take my name off their database and they insist on my ID, cell no and account number. They don't seem to grasp the concept of I DO NOT HAVE AN ACCOUNT WITH THEM. They clearly bought a whole lot of data from someone and are now harassing me with phone calls.